Like, I don't know anything about Perl, Win32 and IPC, but if it were Unix, I would use some Expect stuff to handle this. The open FIFO, "/path/to/program|"; might actually work, at least on my Unix boxes.

But as I said, I really haven't been dealing with Win32 much. However, according to CPAN the Expect module should be working with cygwin perl.

And you do know about the security implications of storing a cleartext password in a script, dontcha?