Hi All,

Can anyone help out with this one. In the very shortest terms, what I am trying to do is validate entries in cells that are populated by a formula.

The basics of the sheet is that it contains 5 columns and 11 rows, the 1st column contains fixed data, the second is validated by a list using a named range contained on a different sheet. The 3rd/4th and 5th columns are populated by a vlookup formula, by taking the data from column 2 and looking up data contained on the same sheet as the named range.

The main problem (as you have probably already guessed) is that I cannot validate the cells that have vlookup formulas in them. An example of what I need to achieve is that the user selects 11 items using the validation lists to populate column 2. Following this columns 3/4 and 5 will be poplulated by the vlookup formulas. It is possible that in one of these columns, that there could be four entries of data that are the same, but the user is only allowed three. What I would like to do is prevent the fourth item being entered.

I am able to do this with a rather lengthy IF, OR formula, however I would like to create a pop up for the user rather than a line of text on the sheet. I'm very new to VBA, which I suspect is what is required here, therefore if anyone can provide any help/guidance here, it would be very much appreciated.

Many Thanks

Lee