The Right Mouse Button's number value (We're talking about inside the code) is 4. Look.
function Armor::onTrigger(%this,%player,%slot,%val){if(isObject(%player.getMountedImage(0)))
{
%item=%player.getMountedImage(0).getName();if((%item $= "AK47CBImage" || %item $= "AK47CBImageScoped") && %slot $= 4 && %val)
Part of the function for my iron sights. Notice how it says slot $= 4. In which case is RMB. I'm asking what is the number value for walking, which for me is LShift.