If you go to Advanced Search, there is many more options to specify your search. You can search by category (VM, Thread, Group, etc.), username, and several other things. It is a nice feature for just such a purpose.;)
I believe the character limit needs to be increased. I just sent a vm saying "the villains of Twilight Princess" and it got past the limit. To ensure posts are higher in quality the limit needs to be higher. Being able to post the subject of a sentence and getting past the limit just isn't enough.