What is the FOOBAR in your item descriptions? You can pretty much pass anything that you would pass in a filter:
** Opens in story river. Note the day notation has to be without dots for "sameday" to work:
** Search for python :
** Link to a filter expression based search for all Prompted Introspections which mention "Vacation":
Note that you have to convert spaces to %20 in order to pass them as URL's. This could be done in a macro, possibly, using the url-encode filter.
You can select tiddlers that contain mode settings, but I would be surprised if you could set them with a url. That would require a on-open action tiddler, I think. Is there such a thing?
Good luck!
-- Mark