RSS Feed XML HTTP POST Syntax

Hi,

Im making RSS feed submission software...(because I have over 1,00 sites and I can't find any software that will let me load them all in and submit them with one click)

So, I have a list of ping sites like:
http://hiderefer.org/?http://blogsearch.google.com/ping/RPC2
http://hiderefer.org/?http://1470.net/api/ping
http://hiderefer.org/?http://api.feedster.com/ping
http://hiderefer.org/?http://api.moreover.com/RPC2
http://hiderefer.org/?http://api.moreover.com/ping
http://hiderefer.org/?http://api.my.yahoo.com/RPC2
http://hiderefer.org/?http://api.my.yahoo.com/rss/ping
http://hiderefer.org/?http://bblog.com/ping.php

But, each time I try so submit the feed via the http POST I get a xml error.

So, what is the correct XML format for pinging Rss feeds?

BTW, Im coding in .NET