You can lookup AHK help file Contents->Hotkeys for usage of modifiers.

For example,

To use more than one modifier with a hotkey, list them consecutively (the order does not matter). The following example uses ^!s to indicate Control+Alt+S:

Code:
^!s::Send Sincerely,{enter}John Smith  ; This line sends keystrokes to the active (foremost) window.return
For R and Shift-R, I will include the following codes

Code:
~R:: .....              ; R 

~+R:: ....             ; shift R
Can't you use ` hotkey instead of ~ ?

Button 4 & 5? Not sure, but you can look under KeyList. I found XButton1 and XButton2.

BTW, there is a gaming forum under AHK site. You may have more lucks over there.