select IP in vb6 to send a http request over

I have a need to do a http request via a com object in vb6. The
server has several IPs bound to the nic card and I need to round robin
my http request to the internet using a unique ip address for each
call. I am told by the techs at amazon.com that this can be done I
just dont know how to do it.

Currently I am using the XML object in vb6 to make the http request
but could use any tool to make the request. Does anyone have a
solution?

thanks, JBtx