Ah, Of Corse! Thank you so much Guys! I can't believe I didn't think of that...'

Ok. Now, I have one more thing, right now.
A menu were you can change your Party members manually. I can't find one
on any event commands. Also, I wanna know if there's a way to make it so that only previous party members can join (for characters the person has not met yet.).
Please Help if possilbe.
and thanks again!