my $s = 'A3xyz45M98AB7Z9';
local $, = ":";
print split /(?<=\d)(?=\D)/, $s;

##</code><code>##

my $s = 'A3xyz45M98AB7Z9';
local $" = ":";
print "@{[split /(?<=\d)(?=\D)/, $s]}";