use strict;
use warnings;

my $line = 'some text <CS_REFCLT>12121</CS_REFCLT> then some text <CS_REFCLT>4654</CS_REFCLT> here';

my (@value) = $line =~ m|<CS_REFCLT>(\d+)</CS_REFCLT>|g;

my ($value) = $line =~ m|<CS_REFCLT>(\d+)</CS_REFCLT>|g;

$" ="\t";

print "Array: @value\n";
print "Scalar: $value\n";

prints:
-------
Array: 12121    4654
Scalar: 12121