I access the Internet though a proxy with both winuae and an A3000t. You set up the proxy the same on winuae as a "real" Amiga. In your example you would enter the proxy in the Ibrowse settings. I usually use Aweb and with it you enter the port nume after the proxy address and a : ie proxy.url.com:8080 In Ibrows the proxy settings are in the settings menu then choose the plus sign next to network then click on proxy. Hope this helps.
Regards,
Xerxes