Trying to build F5 http authentication monitor

Anyone have experience building a POST in the send string including username and password? Note: The authentication type is not basic.

SEND STRING: POST /Home/Login HTTP/1.1\r\nHost: f5.lab.domain.net\r\nContent-Type: application/x-www-form-urlencoded\r\n\r\nUserName=foo%40@bar.com&Password=foobar

RECIEVE STRING: 302 found.

The above doesn't seem to work as expected however I can get a valid response using curl. The above command was built using the post data from the curl output.

Also is "Host:" required in the POST? If so that above can't be correct simply due to the fact that the Host would be subject to change depending on the pool member to which the POST is sent.

Thanks in advance.