i think.....

it's possible use a variable out a awk in the awk ???

ex.

A=20071225

awk '{ print "the value is" $a }'
OR
awk '{ print "........"; c=10; print $c ; c=$A ; print $A}'

for a external variable is possbile use in the awk ???

You can do :

A=20071225
awk '{ print "the value of A is" '"$A"' }' infile

A=20071225
awk -v A="$A" '{ print "........"; c=10; print $c ; c=A ; print A}' infile

A=20071225
awk  '{ print "........"; c=10; print $c ; c=A ; print A}' A="$A" infile

export A=20071225
awk '{ c=ENVIRON["A"] + $1; print c}' infile