Hej Sundialsvc4 and thanks for your post,

I've done some changes in this subroutine so it looks like this now:

my @entries;
my $previouskey = "";

open (KOF, "<$konfil") or die "Kan inte \xF6ppna filen $konfil"; 
open (NYF, ">$nyfil") or die "Kan inte \xF6ppna filen $nyfil";
flock (NYF,2) or die $!;
my $offset = 0;
while(<KOF>)
{
    chomp;
    $value =~ s/^\s*(\S*)\s+$/$1/;

    if ($key =~ /^(.*)(\d+)$/) {      ##### ####  ####
        $key = $1;                    #   # #   # #   #
        $entries[$2]{$key} = $value;  ##### #   # #   #
    next;                             #   # #   # #   #
    }                                 #   # ####  ####

    unless ($key eq $previouskey || $previouskey eq "") {
        $offset = 0;
    }
    $previouskey = $key;    
    $entries[$offset]{$key} = $value;
    $offset++;
}
 
my @sorted =  sort { $a->{'NYTT'} <=> $b->{'NYTT'} } @entries;
my $pers =0;

foreach my $e (@sorted) {
    print NYF ($e->{'UID'}, "|", $e->{'FNA'}, "|", $e->{'ENA'}, "|", $
+e->{'PRE'}, "|", $e->{'NYTT'}, "|", $e->{"PRI"}, "|", $e->{"FOR"}, "|
+", $e->{"CMG"}, "|", $e->{"MEX"}, "\n") if( $e->{"UID"} ne "" || $e->
+{"FNA"} ne "" || $e->{"ENA"} ne "");
    $pers++ if ($e->{"UID"} ne "");
    }
close KOF;
close NYF;
[download]

and it seems to work !

Thanks for pointing me to the right direction