use strict;
my $str = '0320818717nullnullnullnullnullnullnullnullnullnullnullnullnullnullPubDSK_1nullnullnullnullnullnullnullnull341280nullnull1016041506FOREROnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullAYALAnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullDIEGOnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullALEJANDROnullnullnullnullnullnullnullnullnullnullnullnullnullnull0M19920113150010O+null2[STX]CnullZ ÇÇ{jÅYP¡B$MâDz<¼ßh[DLE]Fѱa[DC4]íBnjéMéoÜ]ê$£uàºúgòVîYòZdæsÖnull¢«¡GïakªúUñ,~á`¡Üaô]jf$Hüÿ[FF]Q|Ñ[DC4]ª[DC4]de忱¬,nullÿRáç[»Xkb¢9ºÀ¥`ldpjLvR}WÆUkvmez[çZ÷´«i}[ù*ë[DC4]AB M$ null7[STX]Cnull[DLE]Y ÇÇ\\zoÆwígÿïª`Öm[STX]æ¿XÄ$JüFÉAâEs«K\\V§Kc¢düöUÑ5c-<:«ùåLöB£7Ñ#JlïG[ESC]á2ÿ[FS]æmò2èiî@?Xï)É9ld[4àüüGéDcRc¿]GdoV5[DLE]2,Jï`T;ägom}sçuO<Zln5ïsCgRpêtG_Vö1mcäBh[DC2]M ìRWöè²null[SUB][ESC]?[SUB]¦a<Të[SOH]ª[DC2]eë^0aïM[DLE]c[CR][DLE][j [SO]nullXOy`h_xgú[SYN][CR]';
my $regex = qr/(.*)(\D{2})(\d{10})(.*)/mp;
my $subst = '$3';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html