If you can find cordinates in a different form to the one you quoted we may be able to help you, but anything that starts with a map number won't be useful. Not least because there are five different scales of OS map and, for example, Landranger map 119 doesn't cover the same area as Explorer map 119.
An OS grid reference should look like this:
TG 51409 13177
The two letters at the beginning define a small square of the UK, and the numbers the coordinates within that square. If you can get your coordinates in the standard OS form then there are some sites on the net which will help you convert to or from normal GPS coordinates.