Hi smart hackers, only u can help me ^^

Ok guys, it's a little complicated, first of all this hacking issue is related to cell-phone and not computer, but I think maybe you can help.

What I need is, to pretend that a particular someone has sent me a msg on my mobile, with this someone's number showing as the sender, while this someone didn't really send anything.

I hope I could make it clear ^^ I'll appreciate your help very much.