help! drum triggers using audio file - sonar 7 pro

hey guys,

our studio uses sonar 7 producer and i'm having trouble figuring out how to set a drum trigger to read an audio file at a certain threshold. not even sure how to set a drum trigger period. i've always used the live clips, but this particular kick drum sounds nothin' but nasty, so i need to replace it on his beat (no click).

please share any info you can, or maybe point me towards a tutorial.

thanks guys!
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oh, and i'm mixing right now, so any info ASAP would be seriously appreciated! :)