You question is confusing. POST is a method for sending data to that remote server, not the format of the retrieved data. And the example URL that you gave is a GET, not a POST.
To GET a page from a remote server, with args:
$page = file('http:/http://www.whatever.com/whatever.asp/?value1=1/');
$page now is an array of lines; you may wish to implode() it.
If the remote server requires that variables be passed as POST and not as GET, then you should look here:
http://px.sklar.com/code.html?code_id=313