Lennona52

Hi! So I'm new to main stage, so I have a question about triggering samples/playback. I'm looking to play the first 30 seconds of an MP3 file and have it set on a key before I come in with the song itself. I have a playback set up with Play/Stop, but to stop the sample I have to hit the button again. I want it to stop on its own without me having to press another button, and I don't want the song to continue. I'm just looking to have the first 30 seconds of the MP3 file, but it doesn't seem like I could trim the file. Any idea what I should do to have the sample activated on a key but it will stop on its own? Thanks in advance!