Check out ez_where,
http://www.brainspl.at/articles/2006/06/30/new-release-of-ez_where-plugin
It might help with you range problem
or you could do
/(1[5-9]|[2-8]\d|90)/ which might not be the best way of matching that but i believe it'll work
Let them provide the SQL where clauses?
It could be a Very Bad Idea, but either way the plugin's really nifty.
