smaller increments when placing image on object

I have a curved wall which starts flat and curves at the bottom towards the camera. I have a pattern which I want to repeat. At the mooment the pattern repeats well with a few small repeat adjustment tweaked. The bottom (at the bend) needs to be shifted in smaller increments just to line up. Is it possible to have say

Repeat
X 4.4 Y 4.78 (This keeps rounding up to 4.8)?

Im not yet sure how to edit UV mapping to align everything this way (if possible). The pattern has lines at angles which need to meet up.

cheers

lister