Getting ascii code by keydown event

Question

Hi friends.
I have a ReadOnly textbox. I want to get ascii code when I press a key. By e.KeyValue I can't do it. For example when I press '2' key I have the keyValue of '2', and when I press '2' key while shift key is in down state, again I get '2' keyValue. But I want to have '@' ascii code in that case. I can do it by handling all keys states like shift and capslock, but it needs a big code. I want to know, is there any other way for it?