What do you mean?
The pinkie switch is either a shift button enabling three additional programmable button modes or it is a programmable button in modes 1, 2 and 3. Which ever you decide to make it is determined in the profile editor.
The modifiers in game are keyboard buttons/keys. i.e.: shift, control, alt. You can't make the pinkie button a modifier in the game but you can program it in the profile editor to just about anything under the sun. Well I can anyways. :)