Conditional formatting when values equal values from another sheet

hi brianlg. you can either do this formula as a helper column in Sheet1 & use the Conditional Formatting to lookup this formula or do these steps to avoid the helper column.

1. go to Sheet2 & select your range of data say from A1:A10.

2. you should see a name box below the ribbon & on the left of the formula bar. it shows the cell reference. click on that & type a name. i'll type Reference1. Press ENTER. do the same for B1:B20 & name it Reference2.

3. go to Sheet1 & select from say A1:B20. go to Home -> Conditional Formatting -> New Rule -> Use a formula to determine which cells to format -> Format values where this formula is true:
=SUMPRODUCT(--(Reference1&"-"&Reference2=$A1&"-"&$B1))

4. format to bold & click ok

using helper column, you can skip step 1 & 2 & use this formula in step 3:
=SUMPRODUCT(--(Sheet2!$A$1:$A$10&"-"&Sheet2!$B$1:$B$10=$A1&"-"&$B1))