you could make some aliases that would help you do this.
One option would be to make an alias that had all of your favorites websites, so you could type something like "myweb mynet" and it would filter down to www.mynet.com
and launch it.
Or you could make an alias that matched any string and opened www.MYSTRING.com
that could be used similarly.
Or you could try the farrfox addon for searching web bookmarks in firefox and internet explorer (requires a bit of extra work now with new versions of firefox).