DND ON is correct, you can send whatever CPN (calling party number) you want (even ones you don't own). Proved this from a client by calling him from what appeared to be his own cell phone. A couple of gotchas, though:
Some carriers and some states won't allow you to send caller ID not your own (I think LA doesn't, for example).
Long Distance can get you! If your LD carrier at main site sees a "foreign" caller they may bill that number as a "casual" biller (no account), so be sure you check this out. Had one client who registered only his main number and after a couple months discovered that all of his LD from other DIDs was being billed at casual rates, which meant a monthly fixed charge for each plus minute charges.