I use a variable for that.
Normally a script would start with:
on *:TEXT:sometrigger:*:{
I replace that with:
on *:TEXT:sometrigger:%botchannel:{
Now, if you put in the variables window a variable:
%botchannel #channel1,#channel2,#channel3
The above script will only work on the channels that are specifed in that variable.
I like having it this way, since I can easily control where the scripts will work, and where not...
There are other ways, but this is what I use for it.
Good luck.