@Eddie-Jr.-Panes
I worked on it further and came up with something more generic:
(?-s)^(?:.*?(;|,|\t)){FIELDMINUS1}\K(?:.*?)(?=(?1)|\R|\z)
It will match various delimiters: ; or , or tab. To add or remove delimiters, just change this part of it: (;|,|\t)
It will also work (and highlight nothing) for a field if that field position occurs in the middle of two consecutive field delimiters (also stated as two delimiters occurring back to back).
I saw a slight problem. If FIELDMINUS1 is zero, and the first field in the data to be matched is empty (meaning a line starts off with a delimiter rather than non-delimiter), then the match is incorrect. Maybe guru of gurus @guy038 could fix this problem,?