I want to forward one of our extensions to an external number? Is this possible with my FXT-224 setup?

Possible?

More than likely, with proper technician-level programming to allow the user-level programming.

Practical?

Depends on how many lines you have, what type lines they are, and how many people will be forwarding. If it really is one, then at least the last part isn't an issue. Experience tells me, however, that once one starts, others want the same capability.

Justin