Squid and HTTP Host value

["Julian Gilbert" <julian@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

I am trying to configure squid 2.5 and looking for some assistance. When I 
make client request to squid in the form:

GET http://66.102.9.147/
HOST www.google.co.uk

the squid proxy makes the following request to the web server:

GET /
HOST 66.102.9.147

How do I configure squid not to overwire the host value? The request from 
squid should be sent as:

GET /
HOST www.google.co.uk

Many Thanks,

Julian Gilbert