Otherwise known as "The Transposition Trick."
I haven't done it in a while but basically you set the pitch range then push the pitch bend fader all the way up or down depending on the range of the melody line. Then transpose the MIDI.
It's in the options tab and this is straight out of the VI (not Pro) manuel, page 35 I think.
"Pitch Range Click-drag to set the master pitch bend range (as controlled by the Perform tab > Pitch Bend slider)."
So set it to a semitone then just push the fader up or down. Although In my experience a whole tone worked better for some reason.
BTW it would be nice if this were just automated some how in the next generation of VI Player (hint! hint! VSL 😊)