Fine tuning samples in sampler

Hi. In Sampler, when creating a custom pitched instrument (pipe organ!) fine tuning the pitch of notes in individual sample zones seems to be a massive pain as I can only scroll up and down via the mouse in increments that are far too coarse for pitching samples to accurate tune…and the auto tune function is not in itself accurate enough. Any idea how to refine the increments so I don’t have to resort to keying in a guessed pitch, and then listen, then adjust by keying in again. Too long winded for words! Thanks for your time!