Change program mid track

(kinda new to this so I’m not 100% sure I’m using the right terms)
So I’m trying to find out if there is a way so that when I get to a given point in a track I can change the program that’s played.
What I want, for example, is to start a track in say Grand Piano and then at, for example bar 4, change it to Church Organ.
Is this possible? How would I do it?

Are you using external MIDI gear or are you trying to change the program of a VSTi?

EDIT: I’m sorry, I just realized I’m in the Halion Sonic forum. I don’t believe HS supports MIDI program change (someone feel free to correct me). I think the intent is to just load the 2nd sound onto a 2nd program slot. You can run all slots from a single MIDI track by assigning the MIDI notes to MIDI channels.

Thanks for your reply. Can I be a pain and ask for a more basic explanation? I’m really new to Cubase and VSTs and whatnot. Thanks again