Pretty sad nobody engaged to discuss. If you dont want to go and keymap all your keyboard and you need to use @ or # or | the most easy way is to edit like this your .properties
EXAMPLE:
Use: MODIFIERKEY_RIGHT_ALT, MODIFIERKEY_LEFT_CTRL to "emaulate" Alt Gr in spanish keyboard
I found out the it must be RIGHT ALT and LEFT CTRL if not I ended up with a m after @
Like @m or |m
ASCII_40 = KEY_2, MODIFIERKEY_RIGHT_ALT, MODIFIERKEY_LEFT_CTRL
// 64 @
Hope it helped,
SB