As far as I know, you cannot detonate satchel charges using the setdammage command.
The only way to make them blow up is to have a unit plant them, then tell the unit to touch them off (as pointed out above in this thread).
However instead of using a satchel charge, you could just make an explosion using something like:
boom = "shell125" camcreate [ x,y,z ]
If you really needed the satchel charges there, you could camcreate them, then have the explosion and at the same time move the satchel charges away...