Try this simple script for your line:

#!/usr/bin/perl -w
use strict;

my $line = "0010 0010 text // text // JOHN DOE";
chomp $line;

if ($line =~ /^(0010 ){2}(.*\/\/ ){2}(.*)$/) {
         my $name = $3;
}
[download]

UPDATE:
Also:

my $name = "0010 0010 text // text // JOHN DOE";
chomp($name);
                                                                      
+          $name =~ s/^(0010 ){2}(.*\/\/ ){2}(.*)$/$3/i;
print $name;
[download]