Since the data / time is obviously fixed-length, there's no need for a two-step process or regex.

my $string = '01:01:2000,14:01:12,1.584167';
my $min = substr($string, 14, 2);
print $min;
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Or if you really MUST use split:

my $string = '01:01:2000,14:01:12,1.584167';
my $min = (split /:/, (split /,/, $string)[1])[1];
print $min;
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