[exim] Need a little perl advice

OK - I'm new to perl. Trying to do something simple. So the line below
prints out the string I want - but - I want to pass the string to a
subroutine and can't figure out the syntax to do that. This is probably
simple - so laugh at me.

print "insert ignore into karma (ip,expire,hostname) values
('",$ip_address,"',",time()+200000,",'",$hostname,"');\n";


Here's what I'm trying to pass it to.

sub mysql {
my $query = $dbh->prepare($_);
$query->execute;
}

Thanks in advance.