According to the advanced search help it does
http://frothersunite.com/phpBB3/search.php :
Search for keywords:
Place + in front of a word which must be found
and - in front of a word which must not be found. Put a list of words separated by | into brackets if only one of the words must be found. Use * as a wildcard for partial matches.
A simple test of searching for 'boolean' (without quotes) shows you post as first hit and then a 'boolean -exclude' (again without quotes) does not return your post.
This is the same in the search box at the top of the page and advanced search screen. Not convinced it would work with wild cards but despite not knowing what version the board is on or how the parser works that well I'm pretty sure the wildcard gets priority.
Any moderators have more technical knowledge than me help here?