How to modify location names on the map?

[Ricky B]

The 346 and 667 are simply decimal parts of the coords, I am fairly sure.

But the map in the game has only simple coords like 34,126 without decimal parts.

Right, but the text label isn't exactly centered in some way around a hex. Try adding labels in nearly the same spot, on a test sub map maybe, and check that submap file in a text editor. The labels will have slightly different coords. Like this:

2.46154 4.6 0 0 0 Test1
2.23077 4.56667 0 0 0 Test2
2.46154 4.3 0 0 0 Test3

I created all of these in hex 2, 4, slightly separated from each other. But if you know artillery coords, you have the offsets to the larger grid to get to the specific location on the map.