Conditional Formatting

[LEna25]

 I am trying to find a way to highlight one cell if there is an X  in one of twelve cells. I have been using this rule =COUNTIFS($C$2:$E$2,"X") and it works great, but only for two cells. If I put more then two cells in the formula I get an error message. For example if I change the formula to this: =COUNTIFS($C$2:$E$2:$Q$2,"X") I get the message that I may not use reference operators. Why does it work for two cells but not more then two?  What am I missing? 

[#2]

@LEna25 

=COUNTIF(B1:M1,"X")=1

You can try this rule for conditional formatting.

=$N$1:$N$7

This is the range the formatting applies to in my example.