ActiveX - redirect browser with POST

[chitza2k]

I have an ActiveX form in a HTML and I want to send some parameters to a PHP script (somethig like http://myhost/myscript.php?param=value) that processes the value and displays a page.
But the thing is I don't want anyone to see the value of the parameter. So I figured I should send it via POST method (instead of GET in the URL).
Can anyone tell me how to do it?
I tried using indy IdHTTP component's Post method, but I don't really know what I'm doing ...