How to determine specific invoice Trx Type from a sales order tax code

Dear All,

I need to define a rule (pre or post transformation rule) to determine a Transaction Type if a specific Tax Code is present in the sales order. Currently, I have set up a pre-transformation rule that determines the transaction type based on the order type.

For example:

- IF Order Type= "a" THEN Transaction Type = "A";

- IF Order Type= "b" THEN Transaction Type = "B";

- IF Order Ty.....

I would like to add an additional condition based on the tax code.

For example:

- IF Order Type = "a" THEN Transaction Type = "A";

- IF Order Type = "a" AND Tax Code = "1" THEN Transaction Type = "A1";