SitedMacro works very well and exactly as described.
One feature request: I am using it sometimes on captive portals where the URL ends in a "?" and then has a custom generated random string like "234522345" appended at the end. On these sites the macro doesn't trigger because the URL after the "?" doesn't match. Is there anyway to get this kind of site to work? Maybe a checkbox to ignore anything after a "?" or way to edit the URL and put a wildcard into the name.
Thanks for the nice plug-in!
EDIT TO ADD: Thanks for implementing the feature I requested!