Here's an extract of how I use the XMLHTTP library in the SMF add-in:

Dim oHTTP As New XMLHTTP

sURL = "http://some.url.com"
oHTTP.Open "GET", sURL, False
oHTTP.Send
If oHTTP.Status = "200" Then
sData = oHTTP.responseText
Else
sData = "Error"
Endif

I'd use a later version of the XML library if you have it. You should have
version 3.0 -- that's what I use for the SMF add-in. I used to use version
5.0, but found out quite a few people didn't have it (or version 4.0) on
their machines and rolled back to 3.0.