(1)
my $dbh->do("INSERT INTO tbl VALUES (".param('Col1').",".param('Col2').",".param('Col3').")");

(2)
my $Col1 = param('Col1');
my $Col2 = param('Col2');
my $Col3 = param('Col3');
my $dbh->do("INSERT INTO tbl VALUES ($Col1,$Col2,$Col3)");

(3)
my %params = Vars;
my $dbh->do("INSERT INTO tbl VALUES ($params{'Col1'},$params{'Col2'},$params{'Col3'}')");