It'sprobably not what you wanted, but qwerty's
sendkeys alias can send keystrokes to your computer, so when you type this in some editbox
/sendkeys %{TAB}{F6}www.mirc.com
it would change to your browser if you've got one active, and type a great url in the address bar. You don't really want such things in a script though, especially not with remote triggers.
ps: yes, I deliberately left out the {ENTER} in the example above
ps2: in a script use sendkeys % $+ {TAB}{F6}www.mirc.com
