Problem Converting 32 bit Add-in to 64 bit

I have an add-in I wrote using Visual Studio 2005. It works fine on 32 bit machines but I can't get the program to compile for 64 bit. I've changed the Platform to x64 and unchecked Register for COM interop. I added  "%Windir%\Microsoft.Net\Framework64\v2.0.50727\regasm" /CODEBASE "\$(TargetPath)" to the Post-build event command line. When I try to build the program it gives me an error that says "The command ""%Windir%\Microsoft.Net\Framework64\v2.0.50727\regasm" /CODEBASE "C:\VB\VS2005\PAE_Addin_x64\bin\PAE_Addin.dll"" exited with code 3. I suppose this is due to the fact that I'm using a 32 bit computer and the directory "%Windir%\Microsoft.Net\Framework64\v2.0.50727\regasm" /CODEBASE "\$(TargetPath)" doesn't exist. I'm not sure how to get my add-in to register itself though. Any ideas?

SolidworksApi macros