Okay, highlight cell A2 down to the bottom of your range, then click on conditional formatting, manage rules, edit rule etc., and use this formula instead:

=INDEX($B2:$Z2,MATCH(TODAY(),$B$1:$Z$1,0))="x"

Note the $ symbols (and change Z to whatever column you are likely to use). Excel will automatically adjust the row reference (2) to suit the other rows that you highlighted to begin with.

Hope this helps.