link to posts in both of two categories

I’d like to present my users with a link to posts that belong to both of two categories (boolean ‘and’, not ‘or’), and can’t figure out an easy way to do it. If it were one category, I could just do the permalink (e.g., mysite/category/site/category_name/), but it doesn’t seem that WordPress supports query logic in its URL strings.

I’ve read a bit about the query_posts function and the use of category__and, but this seems to be a heavy-handed way of going about it, and I don’t know how I’d insert the result into a link.

I’ve seen plugins that allow you to directly search posts using Boolean logic, but I can’t figure out a way to encode this into the a href=… syntax I’ll need.

Many thanks for your pointers.

Jim