Formula for making text in column A and D give a unique identifier in column B

hello everyone
im trying to make a formula to give me the text in column A,, plus the test in column D, plus unique identifier (01 sequential onwards) for my table as the attached sheet
i have many versions of the FERxx so want to end up with (text column a) + (text column D) -001 for the first example where there is FER23 and FAT in columns A and D, then use the -002 identifier when i have the second time "FER23" and "FAT" in columns A and D.

im very new at getting the formula to work on the sheet, but do know how to enter a code into an excel sheet.

many many thanks for any help you can give me .
Cheers
Steve

many thanks for the help, but it just adds the row number in in the final part of the text for that cell.
sometimes i might have the FER23 and the iFAT in rows, 3, 5, 9 , 10 (example) but it wouldn't number it as 01, 02 , 03 and 04, it numbers them exactly as the row number.
i need it to only give it the sequential 002, 003 number where the next example of the combination of FER23 AND the iFAT exist.

many thanks for any help