Run function ASYNC??

I am trying to have my installer ping my server when the installer starts using this code:

metadl::download_quiet /TIMEOUT=500 /MAXTRIES=1 "http://example.com/installtrack.php?action=start_installer&error=&options=" "$temp\del.txt"

This works but if my server takes 5 seconds to respond the installer hangs for 5 seconds waiting. Is there a way to do this like "ExecDos::exec /NOUNLOAD /ASYNC" where the installer continues and doesn't wait for a response?

You could try http://nsis.sourceforge.net/BgWorker_plug-in