I'm not sure I know exactly what you mean. If you mean you want to drop satchels while playing a map and then detonate them beyond the usual distance limit with the radio, I haven't a clue but I bet someone else does.
If you mean you want to designate spots at design time that can be blown at play time with the radio then you might try game logic units with a simple script that will camcreate explosives at their location when you use the radio.
Attached is a sample of the basic idea. The explosion is weak because it's using a shell. The timebomb, (which is the recognized name for a satchell, I think) delays for about 15 seconds before blowing. Try other explosives or maybe someone with a better idea will jump in here.
mcnorth