It looks like your game’s map has a “slanted” grid where the rows (numbered) follow the hex rows which are 30 degrees from horizontal rather the more common horizontal rows which would “zig-zag”. Vassal is set up for the “zig-zag” style rows (or columns). I remember a feature request (and discussion) to number with “slanted” rows like the printing on your game’s map.
Edit: The expressions shouldn’t have the modulo portion, and it looks like the offset needs to be subtracted. See the next post for the updated Location format expression.
You’ll need to convert the column letters to numbers (see: Manipulating Strings or Counting by Letters) and use the Modulo operator to generate an increasing offset to add to (or subtract from) Vassal’s row number. For the row I’m thinking of somethin like: {(“ABCDEFGHIJ”.indexOf($column$)/2)+(“ABCDEFGHIJ”.indexOf($column$)%2)+$row$}. The string “ABCDEFGHIJ” will need to include all the column designators. If the column designators include some two-letter columns like “AA” or “AB” then a different string manipulation will be required. I believe Vassal only uses whole numbers and truncates quotients, discarding the fractions; otherwise the part of the expression “ABCDEFGHIJ”.indexOf($column$) will need to be in a round up or round down function.
So the Location format would be like {$column$+(“ABCDEFGHIJ”.indexOf($column$)/2)+(“ABCDEFGHIJ”.indexOf($column$)%2)+$row$}.