The script should look kinda like this. (Not sure about this)
_Bombarea = NearestObject [_man,"Smokeshell"]
#check
@_man ammo smokeshell == 0
~10
shell1 = "Shell120" camcreate [(getpos _bombArea select 0) + 1, (getpos _bombArea select 1) + 2, getpos _bombarea select 2]
shell2 = "Shell120" camcreate [(getpos _bombArea select 0) + 2, (getpos _bombArea select 1) + 2, getpos _bombarea select 2]
shell3 = "Shell120" camcreate [(getpos _bombArea select 0) - 1, (getpos _bombArea select 1) + -1, getpos _bombarea select 2]
shell4 = "Shell120" camcreate [(getpos _bombArea select 0) - 2, (getpos _bombArea select 1) - 2, getpos _bombarea select 2]
~10
goto "check"