Convert a form to HttpWebRequest?

Is it possible to convert this code to a HttpWebRequest, that would be 'called' in code-behind?

<form action="https://www.somedomain.com/cgi-bin" method="post">
<input type="hidden" name="var1" value="1">
<input type="hidden" name="var2" value="2">
<input type="image" src="https://www.somedomain.com/images/Image1.gif" name="submit" alt="">
</form>

I understand starting with this:

Dim myRequest As HttpWebRequest = Ctype(WebRequest.Create("http://www.somedomain.com/Page12.aspx"), HttpWebRequest)
myRequest.Method = "POST"

The server page expects certain hidden fields.  How do you ge ...