Normally, the Shell function does not admit any space or parameter in the command line. I think all you need to do is to use Chr$(34) to enclose whatever in the command line. If you have not yet succeeded, try something like this:

Shell ¡°exe name including path plus an ending space¡± & Chr$(34) & ¡°all the parameters including the email file¡± & Chr$(34)

Hope it helps.