help setting props to look for attacker

it should be simple but for some reason i cant get it to work . all im trying to do is when you spawn a prop from the q menu you you set
[lua]
player:SetPhysicsAttacker()
[/lua]
on the prop you spawned
that way you can get credit for the kill if you decide to prop kill someone.

can someone help me on this please.

so can anyone help me with this?