Using PasswordMaker's account settings should help. You just make a account (inside a folder, and you need to be in advanced view if you aren't already) and set the required url patterns and the needed tweaks for the site. I'll let someone else explain this in more details, or I can help with questions if you can figure this out on your own.
Another thing I have started doing was only using accounts for sites that are way different than normal (as my username is in my settings for example) and when all I need is the upper/lower letters and numbers, I use the Click edition (it's a bookmarklet) as it's easier than setting up a new account in PasswordMaker for just changing the allowed characters.
Mind you, I'm a bit of a power user, so I may do things a bit more complex than a normal person would.