while ($fh) {
  /^Confname/ or next;
  work_with $_;
  last;   ## if you want to process only the first ocurrence of such line
}

##</code><code>##

my @confnames = grep /^Confname/, <$fh>;
## if you want to process all lines:
work_with $_ for @confnames;
## else:
work_with $confnames[0];