Tax Percentage through Z process

Hi,

We are trying to create sales orders by integrating order data through external system. We are planning to use JDE Z process to create sales orders. External system will pass on data to us and we will crate sales order using sales Z process. We are trying to figure out how can we get tax percentage from external system passed to JDE for applying tax at the % sent by external system. In F4211 we can not store tax percentage, it only has tax rate area and tax explanation code. If we not have correct setup in JDE (since taxes