Charcode for different keyboard layouts

Not sure if this is doable, but I thought I would ask to see if anyone could help me out

I’ve created a custom font for the users of my program to use. They input certain characters from this font by using the shift + number keys.
so for eg, shift+2 = characterX

I track their inputs by using String.fromCharCode(X)
characterX= String.fromCharCode(33)
characterY= String.fromCharCode(34)
characterZ= String.fromCharCode(163)
this works fine on UK keyboards as the layout of characters for shift+1-3 is !"£

however on a US keyboard shift+1-3 is !@#
so that needs
characterX= String.fromCharCode(33)
characterY= String.fromCharCode(64)
characterZ= String.fromCharCode(35)

I cant use the @ and # as they are used elsewhere for other characters

is there anyway to force flash to use CharCode(163) when the user presses shift+3 no matter what language they are using??