How to direct awk output to expr?

Is there any way to combine the following two statements into one? I can't figure out how to get expr to take input from the output of the awk call - I've tried piping the output of the awk call into the expr call, and tried using a 'Here' document, nothing seems to work.

export CNT=`wc -l ${QV_FILENAME} | awk '{print $1}'`
export FILE_RECCNT=`expr ${CNT} - 2`

Thanks for any help that anyone can offer.

About a hundred solutions here... For one, awk can do arithmetic.
export CNT=`wc -l ${QV_FILENAME} | awk '{print $1-2}'`

Thanks for the help!

awk '{}END{ print NR -2 }'

count=$(($(wc -l < $file)-2))