Need help with artillery script

[harkkam08 10]

Hey guys I am trying to create a mission where you start of as some rebels and you attack a base that has some empty grad rocket trucks. I am using the high commander module as well. Is there a way to make this truck become a part of my high command menu and then be able to point and click artillery where i want it to go. Most scripts already give you arty and what not I want the arty to be avaliable only after youve taken the piece from the enemy base