Try using \Q and \E to escape the special characters in the split. eg.

#!/usr/bin/perl
use strict;
use warnings;
my($first_line,%records,$sep);
chomp($first_line =readline (DATA));
seek (DATA,462,0);# use seek(FILEHANDLE,0,0) to return to start of fil
+e.
print "Please enter the seperator example line follows,:\n\t\"$first_l
+ine\"\n";
chomp($sep=<STDIN>);
while(<DATA>){
        my @record=split/\Q$sep\E/,$_;
        $records{$record[0]}=$record[1];
}
for my $name (sort(keys %records)){
        print "$name has the value $records{$name}\n";
}
__DATA__
name :-$& value
anim :-$& freagra
nomme :-$& valeur
[download]

Works as follows:

~/tmp$ perl tmp.pl
Please enter the seperator example line follows,:
    "name :-$& value"
 :-$& 
anim has the value freagra

name has the value value

nomme has the value valeur
[download]