executing a function + argument passed in as an argument to another function

[dean]

I seem to be able to do this by....
(de some_fn (Canned_fn_and_arg......

and then executing the Canned_fn_and_arg inside some_fn by doing....
((car Canned_fn) (car (cdr Canned_fn)))

Is this the right way or is there a slicker one?