If you're using XP, download
Powertoys , which is a tiny prog that adds functionality to XP that
should already be built in.
In the options sidebar, choose My Computer > Special Folders and then select "Installation Path" from the drop down list, and set it to whatever you want. I've never used it for this purpose but it should do what you want.
If not using XP, then I don't really know! Maybe someone else will...
