Maybe you need to do something involving this:

Source: https://www.ableton.com/en/manual/midi-and-key-remote-control/

Creating control surface assignments for your computer keyboard is straightforward:

Enter Key Map Mode by pressing the KEY switch in the upper right-hand corner of the Live screen. Notice that the assignable elements of the interface become highlighted in red when you enter Key Map Mode. The Mapping Browser will also become available. If the Browser is hidden, you will want to show it at this point using the appropriate View menu command.
Click on the Live parameter that you wish to assign to a key. Remember that only the controls that are shown with a red overlay are available for mapping.
Press the computer key to which you wish to assign the control. The details of your new mapping will be displayed in the Mapping Browser.
Leave Key Map Mode by pressing Live’s KEY switch once again. The Mapping Browser will disappear, but your mappings can be reviewed at any time simply by entering Key Map Mode again.

Keyboard assignments can produce the following effects in Live:

Clips in Session View slots will be affected by mapped keys according to their Launch Mode settings (see 13.2).
Keys assigned to switches will toggle switch states.
Keys assigned to radio buttons will toggle through the available options.
Please be sure not to confuse this remote control functionality with Live’s ability to use the computer keyboard as a pseudo-MIDI keyboard (see 14.3.2) that can generate MIDI notes from computer keystrokes for use with instruments.

Thank you Jason,

I think Ableton software don't include a functionnality like "enter"...
In fact, what i'd only need is the ability of generate a "enter" with Montage Hardware, maybe a foot controller, a switch... but i didn't find yet

If Ableton software doesn’t include a functionality like “enter”, neither will any remote controller.

The poster is saying that the Enter key on the Montage is not programmable as a trigger button within Ableton. That I believe that is correct. Ableton allows the users to assign midi controllers to nearly any function within Ableton (or assign keyboard keys to control things) Enter on a pc kleyboard will launch the clip that is highlighted by the cursor on the screen,

OP you can use the scene buttons and assign them in Ableton to trigger clips or scenes within the remote mode. You could also try the switch buttons. Not sure if it would isolate a single clip verses any clip. I ended up getting a Base controller used to do it but I also found if you have a number pad on your keyboard that it works well as a scene launcher and its right there.

Yes "c" 😉
Scenes buttons allow to trigger pre-defined clips, so you can patch them to 8 zones, but it means you have to define beforehands, and it can kill the feel of the moment, which is Ableton recording bonus over Logic ProBut .
And you are right, pc keyboard is very good, as you can use Enter to trigger selected clip, numbers for scenes, arrows to move from clip to clip...

But with just the ability to emulate Enter, a keyboard would not have been necessary, with Montage Remote.
And strangely enough, foot controlers don't transmit via Montage Remote

Too bad... 😉

Maybe a plugin or standalone program can do this.

https://obsproject.com/forum/threads/midikey2key-translates-midi-events-to-key-shortcuts.78103/
http://charlie-roberts.com/midiStroke/

... or Ableton's incoming action: https://music.tutsplus.com/tutorials/quick-tip-midi-translation-midi-to-keystrokes--audio-6914

Not searching all the possibilities.

Thank you so much Jason : you were right !

midiStroke is for PowerPC, so not OK for Intel Macs
Bome Midi Translator Pro is OK for new Macs, but expensive (free for windows), it seems very complete and easy to handle

And i've found MidiPipe, http://www.subtlesoft.square7.net/MidiPipe.html
It is free, it has a template for Live Control, you just have to adapt the appleScript for your Montage keys (Scenes buttons send Midi Note around C3, on Midi Port 2, so i doesn't interfere with anything else that you could play or recall).
Simulating Enter in Applescript is : keystroke return

Now i can fully control Ableton with the Montage Remote, and if i dig further in applescripts, i'm sure i could use scenes buttons to trigger further useful shortcuts.

Thank you again for your support !
Alex

No problem - glad you could get this sorted out.

Thank you so much Jason : you were right !

Now i can fully control Ableton with the Montage Remote, and if i dig further in applescripts, i'm sure i could use scenes buttons to trigger further useful shortcuts.

Thank you again for your support !
Alex

Hi OP, can you please explain how this has come along since you posted? Can you please provide screen shots or something as to what you assigned as well as your midi port setup in ableton? I would love to make remote do some cool stuff also but I dont quite understand these midi tools and what they are doing.