See page 37 and 38 of the SampleRobot for Montage manual: http://content.samplerobot.com/Manuals/SampleRobot_6_Montage_Manual.pdf

Page 37 shows there is a "Sample" window which has a key range tab. Note that there are different modes that, by default, the right-hand panes that show tabs will fall into. Selecting different areas in the left-hand side will show different options on the right-hand side. Sorry the description is a little vague. I've only had limited time in front of this software - but that's what I remember from using it (options are not always showing - you have to click on the correct area first).

Then, from the more global area (page 38) around the virtual keyboard is both the quick-select (shortcut) buttons for populating common keyboard sizes (37, 49, 61, 76, 88) but there is also a set of numbers that represent the MIDI note numbers in decimal with up/down arrows to the right of each number. You should see these two numbers change as you select the shortcut buttons. I do not have the software loaded right now so I can't throw up a screenshot or walk through it. But the manual seems reasonable enough to give guidance on this one.

Thanks Jason - Your response was very helpful.