You can't unfortunately, but this is a 'limit' of OSes, and not of perl. So you probably either want to take advantage of multi-tasking in *nix-type shells or fork() off at the beginning of your program.

prompt> perl source.pl &
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or with perl

use strict;

fork() and exit(0);

print "Now in the child process\n";
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The perl example is a little hackish, but there's plenty of documentation about to explain it all.
HTH

broquaint