$line =~ s/A.TL5F00/+TL\\F5C/g;

##</code><code>##

use warnings;
use strict;

while (my $line = <DATA>) {
    $line =~ s/^A.TL5([EF])00/+TL\\${1}5C/g;
    print $line;
}

__DATA__
A.TL5E001100.TAV
A.TL5F001100.TAV