It would be nicer to allow to trigger a popup on rightclicking a HOTLINK event as a more general case.
on ^*:HOTLINK:#*:*:return
on ^*:HOTLINK:#*:*:if ($mouse.key & 16) showpopup MYPOPUPNAME
menu MYPOPUPNAME {
...
}
It would require a new command
/showpopup to trigger a context menu and custom menu definition names outside of channel,nicklist,etc. (though showpopup could theoretically take a .ini file or some other method). Other than that, it should allow people to define custom popups for all hotlinks, not just channels.