Sending the request in POST

Hi Guys,
I am very sure that its a common scenario but I did not find concrete solution to this. Basically I have a Web Application which needs to be integrated with third party web application. The third party team has given us the URL to hit with specific parameters. but we have to hit them with POST request instead of get. That means I cannot use Response.Redirect() method. I googled it and found various articles related to it, mostly say that I have to use client-side code but I have to use Server Side logic for this. Which is the best way to achieve this from server side?
P.S. : I want to redirect the user to this third party page, if I use WebRequest or webClient class then it will not redirect the user to this third party application. So please suggest something where i can redirect the browser to this third party application in POST.
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