Lastly: it sounds like you have a list of "valid" data in a table. In that case, you may want to investigate the COUNTIF functions. I imagine a scenario like this:
- you have the pasted data on Sheet 1 of the Workbook
- you have the table of valid data on Sheet 2, cells A1..A10)
- On Sheet 3, set up the first test formula "under" the data on Sheet 1. (If the first value is in Cell A1 of Sheet 1 (Sheet1!A1), then put the test formula in Sheet3!A1.
The formula would do a "count" of the valid values, from the table, so a result of Zero means that the data is not in the table (invalid). I just did a quick test: with valid data in Sheet2 cells A1..A10, the formula in Sheet3!A1 is =COUNTIF(Sheet2!$A$1:$A$10,Sheet1!A1)
Note the $ signs are necessary to "lock" the references to the fixed table of valid data. This means that you can copy the formula to match the size of the table in Sheet 1: Sheet1!A1 becomes Sheet1!A2 and so on, but the valid data table stays in one place.