What about

package Bar;
use vars qw($COUNT);

BEGIN {  $COUNT = 0;}
1;

--- script test.pl --
use Bar;
print "count is ", $Bar::COUNT, "\n";
$Bar::COUNT++;
print "count is ", $Bar::COUNT, "\n";
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I get (perl 5.6.1)

count is 0
count is 1
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Did something similar NOT work for you?