Network/proxy input restrictions


My web proxy is at an http address that includes a slash mark (i.e., something like this: Unfortunately, though, the proxy settings page in the System Preferences/Network control panel doesn't allow input of slashes or other non-alphanumeric characters (except periods). Copy/paste doesn't work either if a slash is included. I tried inputting the proxy instead into the preferences of internet explorer, but ie immediately replaced it with whatever was in the Network/Proxies setting. Does anyone know a workaround for this?