I was thinking something like p|sys32 which becomes "system32" (with a tooltip saying of course that in 64 bit systems that should be a SysWow64)
But then I thought that if there was to be a problem with a 64 bit application... should we write plain system32 in the path?
Also, considering that in every case there would already be a %WINDIR% thing.. perhaps this new argument could already include that (for some reasons)