Here, this is on a character I'm working on:
type = ChangeState
value = 1000
triggerall = roundstate = 2 && !AILevel
triggerall = command = "qcf_x"
trigger1 = statetype != A && ctrl
trigger2 = stateno = [200,450]
trigger2 = movecontact
Statedef 1000 is the special move. The trigger2 lines are the important part. It makes it so you can input the command if you're in the middle of using the normals AND if they make contact. This is essentially how it works in Marvel vs. Capcom.
I hope this helps!