Hello
How is the data in Sheet 2 formatted? If the district codes are a string of characters in one cell adjacent to the County, then a VLOOKUP formula will do it. If the codes are in separate cells in the same row, or multiple county records with one code per each record, then you will need something else. Also you mention district names, but you haven't said where these are (unless you mean the codes).
A sample workbook would be good here, including how you want to present the extra detail on Sheet 1.
HTH
Bookmarks