my @content = qw/abcdABCD1234567890xyz 
		    abcd12345ABCD0ABCD 
		    ABCD1234ABC 
		    qwertyABCD12diff7890/;

# push @content,  'ABCD 123 456 789';       # See note "SOLVED!" below
push @content,  'x ABCD 123 456 789';       # afterthought addition 

for my $content(@content) {
	my ($match) = $content =~ /.+?ABCD(.{10}).*/;   # avoid probs w/non-reset of $1
	say "Current array element is: $content";
	if ( $match ) {
		say "\t MATCH! Next 10 char after the match: $1";
	} else {		
		say "\t No match on $content";
	}
}

=head

# SOLVED! why last array element failed to match: it initially began with 'ABCD...'
# BUT the regex required something ( '.+?' ) before ' ABCD(.{10} '
# And a better fix would be to write the regex as:
#        '/.+?ABCD(.{10}).*/'
# or as: '/ABCD(.{10}).*/'

C:\>934221.pl

Current array element is: abcdABCD1234567890xyz
         MATCH! Next 10 char after the match: 1234567890
Current array element is: abcd12345ABCD0ABCD
         No match on abcd12345ABCD0ABCD
Current array element is: ABCD1234ABC
         No match on ABCD1234ABC
Current array element is: qwertyABCD12diff7890
         MATCH! Next 10 char after the match: 12diff7890
Current array element is: x ABCD 123 456 789
         MATCH! Next 10 char after the match:  123 456 7


C:\>

=cut