How do I specify a custom special folder for a setup project?

I know how to add a special folder to "File System on Target Machine" and make it a custom folder. I create one called "Program X" for example. The msi gets passed a parameter, 'ProgramXInstallPath', at the command line which is set to 'D:\SomeFolder\ProgramX'. I开发者_C百科 use the method from the following link to get and set the parameter in another project that I have for custom actions.

http://www.codeproject.com/KB/install/command_lines_setups.aspx

How do I set the location of my custom folder to the value of the parameter, 'ProgramXInstallPath' that was passed into the msi?

I played around some more with my setup project and the "Property" property on Special Folders and ended up getting no where. I found a solution of setting the "Default Location" for the Special Folder to the parameter that I pass into the msi, '[ProgramXInstallPath]'. Make sure that you have the square brackets.