I have many vlookups referencing cell A1/2/3.....with the text: "firstname".
I now need to add to these cells: "last name".

If I add this text, the vlookups search other data tables for "firstname
lastname" and return errors. How can I amend the referenced cells
(A1/2/3...) so that the vlookups only use "firstname" and disregard the added
text ?

Tks