getting data back from another website

I'm sure there's a simple solution to this. In my site, I want to be able to send a query to another website, get some information from it and store it on my own, and I don't have a clue how to go about it. So that you know what I'm talking about, I'll tell you - my site supports about 300 schools in the UK. For each of the schools, I want to be able to get information from the Nominet website (www.nominet.net) to find out the ISP tag that is associated with their domain name. The URL will to pull up the appropriate page will look something like this: http://cgi.nic.uk/cgi-bin/whois.cgi?query=wilden.worcs.sch.uk for a school with a domain name wilden.worcs.sch.uk. I've got a database of domain names, so I want to be able to create the URL, send it off (somehow) and (somehow) process the result, which is (in this case) BTNAMES, as you will see from the Nominet site. Can anyone point me in the general direction of how to do this?