How to pass parameter to call sub template

Hi

I have a custom report about consolidate invoice.

data is as below:

Group 1

Group 2

Current template is as below:

<?call:template1?>

<?for-each@section:G_1?>

<?for-each:G_2?>

<?end template?>

<?end for-each?>

Now i want to create a parameter to print original and copy.

Copy template is as below:

<?for-each@section:G_1?>

<?call:template2?>

<?for-each:G_2?>

<?end template?>

<?end for-each?>

The parameter have 2 value.

while value is 'O', want to call template1, while value is 'C', want to call template2.

I don't know if my understanding is correct, My logic is as below:

<?param@begin:CF_P_PRINT_TYPE?>

<?choose:?>

   <?when:$CF_P_PRINT_TYPE='O'?>