Put the formula in the Conditional Formatting conditions for whichever
column you want the formatting to occur. In the formula, refer to the cell
whose contents you want to affect the formating.
You can use absolute addressing (the $ prefix) if you wish to apply a format
across a range of columns without it changing the reference. So, for
example, if you wanted columns D to G to be affected by the content of
column B, you could use the CF formula
=LEN(SUBSTITUTE(UPPER($B1),"TBN",""))<>LEN($B1) in D1 and it would copy
unchanged across the other columns.