It would better to use Measure and Beats as a reference when trying to figure out when the audio clip is to start... Because you are going to have to use a MIDI Note-on event to trigger, hold and stop the playback of its audio.

Prepare your audio wave so that it triggers from a specific MIDI Note-on event. You can place it on a Key within a Drum Kit Part. Each Key in a Drum Kit Part C0~C6 can hold a different audio sample that can be instructed to play without having to hold the key down. Play automatically stops via "silence detection".

Then edit your sequence to place a MIDI Event precisely at the Measure and beat you wish it to begin the playback. This is the same thing you do with all Montage Parts, you trigger them with Midi Note-on events that turn on and off the audio of the various Parts. You will be doing the same thing with your audio sample.

The Montage can playback a .mid file from the MIDI portion of the PLAY/REC function. Or it can playback a .wav file from a connected USB stick via the AUDIO portion of the PLAY/REC function. Not both, so what you can do is you can convert that .wav bit of audio into a Montage "Waveform". Once it is a Waveform, you can use it in a Montage Part, and trigger it the same way you trigger any audio in the synthesizer, with a MIDI Note-On Event.

Starting playback of your audio waveform will need to begin at a precise Measure and Beat, referencing the MIDI file, in fact you will need to place a MIDI Note-On event on the Track that addresses the Part containing your sampled audio.

You will need to load your audio file .wav into the Montage where you will create a Waveform. A Waveform will be your .wav plus certain Montage parameters that turn it into a "musical" entity. You will assign it a Key which you will use to trigger its playback. Touch the Key to which you assign it, it will begin to playback. Touch the key lightly the audio will be soft, the harder you strike the key the louder the audio will sound.

Like any audio waveform it will continue to sound until the key is released.

To tell you any more would require a better description of your audio waveform... Is it a short event that lasts for a moment, like a sound effect (thunder, a gun shot, a scream, a gong) or is it a long piece of audio (someone singing, a guitar solo, a looping phrase). The reason you need to know this is it will determine whether you can place your audio in a Normal AWM2 Part or a Drum AWM2 Part.

Normal musical instrument sounds tend to be short in nature, so you hold the key when they sound and you let go to make them stop.
Drum instrument sounds can be short as well, but by nature you do not hold the key down to make them play their full term (be it very short or extremely long) Drum envelopes can play and hold automatically until silence is detected, at which time key off occurs.

So in whatever device or program you are creating the MIDI file, you will also need to add the Note-On event that will be responsible for triggering the playback of the Part containing your custom Waveform.

So we need to know from you is how are you preparing the MIDI file for this purpose. Are you using Cubase AI?
What type of audio is it - is it best suited for "normal" or a "drum kit" program.