Changing clefs after Midi Import

Hi, I'm fairly new to the forum and although I've had a look around I can't find the solution to my question elsewhere so I thought I'd ask here. I am importing several Midi files, which are for small chamber groups, (eg. the Max Bruch trios for Clarinet, Viola and piano). I am finding that when the Clarinet goes down into its lower region Notation Composer changes to a Bass clef, and then goes back to the treble clef when the notes go back up again. At the moment I an having to scan right through the piece looking for clef changes and rectifying them. Is there any way I can tell the import mechanism that a strand should always be in the treble clef? ............Thanks ........John