Is it possible to omit elements of enum in inspector?

Howdy there!

Basically I'd to be able to choose a key in the inspector using:

public var theKey : KeyCode;

But KeyCode gives every possible keyboard option and I'd like to omit a few from the list or only allow certain options to appear. i.e No number values or only include letters A to Z.

I feel like this may not be directly possible, but thought it was worth asking: is it possible?

Thanks very much, Romano