Just found out while experimenting that the text it highlights is different if I have the field codes toggled open (i.e. the range text includes the field code value instead of the field's result value). Calculating the offset at that point was 1 character more than the date field's result value. But doesn't work with more complicated fields, or with text fields.

Oddly, it doesn't work if I toggle the field codes 'on' in the function, only if they were toggled on manually. Not sure why that would be, but it is yet another annoyance.

I'll have to experiment some more next week. I would like to solve this problem, but I might have to settle with merging ALL fields in the document to text before running the find function I need to perform.