The 3300 can't do a true "key system". We can sorta "fake it" but it's not really a true key system.
The answer depends on how the keys on your phone are programmed. If they are programmed as DTS, (Direct Truck Select) - then no.
If they are programmed as key appearances - then yes.
You may be able to get an idea as to how they're programmed if when you dial out, you have to press the key and then dial "9" for a second dial tone. (may 8 or some other number - (or 0 for my "down under" friends))
Ralph