If you want to vary the pitch of a single note for making trills, you can use a Multi-point Controller {mpc}. The Controller type will be "Pitch Bend" and the Style will generally be "Absolute."
Typical controller values are: -8192 (one tone below), -4096 (one semitone below), 0 (normal), 4096 (one semitone above) and 8191 (one tone above).