push @{ $userData{$ACTNUM}{$ref} }, $line;

##</code><code>##

for  $ACTNUM (sort keys %userData) {
 for my $line (@{$userData{$ACTNUM}{GCA}}) {
  $ACCTNUM = substr $line, 11, 9;
  $FIRM_ID = substr $line, 660, 1;
  $CURR = substr $line, 661, 3;
  ...