|Conditional Formatting can accomplish what you want.|
I'm guessing that the letter X in you string
are simply place holders and that they can represent any letter or number.
If this correct then with your data in Column A
Conditional Formatting 2007
1) Select your cell or range of cells. IE A1:A100
2) On the ribbon click Conditional Formatting
3) Click on New Rules, it’s near the bottom of the dialog box.
4) Click Use Formula to determine which cells to format.
5) Enter the formula:
6) Click on the Format button
7) Select the Fill Tab
8) Select a Yellow color
9) Click OK
10) Click OK
See how that work for you.