...the last value of the index variable will tell you when you left...
then try this:

my @numbers = (0..9);
foreach my $i (0..$#numbers) {
    print $numbers[$i];
    stopped($i),last if $i > 4;
}

sub stopped {
    my $index = shift;
    print "Stopped at $index\n";
}
[download]

Jeff

R-R-R--R-R-R--R-R-R--R-R-R--R-R-R--
L-L--L-L--L-L--L-L--L-L--L-L--L-L--