Never tried this: but you are assuming something and probably don't realize it. When you connect directly to a web-page (no proxy) you are connecting to port 80 at the remote IP address. (IE: Yahoo might be 204.71.200.67 at port 80)
Most Web-proxies DON'T WORK at port 80, they work at something else. (commonly 8080 or sometimes 5432)
So, when you are defining the fopen, you need to account for this.
This probably isn't the ONLY issue that you have to deal with, but you definitely have to consider this one.
To find out what you need to do, use telnet at the prompt. (with Linux:
telnet proxy.yourcompany.com 80
- not sure about DOS/Windows
)
Hope this helps!
-Ben