If I place him on my lap he'll immediately walk back onto my desk and lay down in his favorite spot. I can't get any work done; send help.
Edit: Sometimes in response I'll reciprocate by laying my head on him and listening to him purr while we snuggle; he's the perfect therapy cat I love him so much. 
Hmm... a decoy.
Sometimes I try to move the mouse really slowly so I don't wake him. I think the easiest setup would be a second mouse or touchpad I can use with my left hand.
You could probably do what the lap cat people do and just stuff a glove and shirt sleeve as a decoy. (They stuff a pair of pants, I’ve done that and it works well until they wise up so use sparingly!)
As long as it’s in the right place, it’ll probably work. For a bit. Might need a decoy mouse attached to it - have any old dead ones?
Unless what the cat wants is those slight movements and the “aww cmon” instant attention it gives :)