[Jimjam]

Bind the f4 key to target group member 4 and to the hotkey with your assist button.

Have the first line with a short /pause* and the second line with just /ass.

This will target player 4 and then assist them momentarily later.

* you may need a second command on line one to make this work. Emotes are good for this kind of thing.

Edit:
Just /assist with no name will assist whoever is on target atm. Type /assist again to assist that target’s target.