Guitar Tablature

A recent thread prompted me to try the guitar tab and I am wondering about a few things.

First off, I think it's really cool how you can input notes on the regular staff and have the tab automatically translate it into tab notation!

I am wondering about the algorithm that is used to do this.

When you play a note on a keyboard instrument, there is only one location to play that particular note.
On the guitar it is different.
There is at least one location for any note, but usually there are two, three and sometimes even four different locations on the fretboard where you can play the same note.

So what happens when Musescore inputs a note in the tab on one string, but you would like to play it on another string?