|A quick but not so efficient solution would be to kill the browser task.|
When the browser opens use
taskkill /f iexplore.exe
If it works too quickly just add a 4 second ping or so, depending how long it takes to load your browser.
There are other ways using software. I believe wget will allow you to use http posts and requests better but I haven't use it myself.
I'd recommend asking someone in VBScript. I know you can do it with a vb script, and you can always use a batch file to open the .vbs file if you need that.