I guess I didn't pay enuf attention in algebra, but - I frequently have to work with columns of numbers that are sequential but also contain letters. I know how to do the formula for automatically entering sequential numbers, but how can that be done when the number also contains a letter. As in A1, A2, A3, etc. Short of putting them in separate narrow columns, there must be a formula for keeping the A constant or locked and increasing the numeric value in succeeding rows in a column. Thanks!