line = 121212, "Simpson, Bart", Springfield<br>

if ($line = /"(.*)"/) {
$1 = "Simpson, Bart"; Now contains

# now run replace on Simpson, Bart
$1 =~ s/,/_/g;

$1 = "Simpson_ Bart"; # Now contains

now put everyting back together.

121212, Simpson_ Bart, Sprigfield
}