Additional cost of purchase when the cost is paid directly to provider

Hi

I am confused on the best way to account for the following.

1. Our company is involved in the purchase of goods across state.

2. The supplier dispatches the goods through transport via a registered transporter.

3. The transport charges are paid by our company directly to the driver.

4. The invoice sent by the supplier does not contain the transporter's charge.

We need to add this cost to cost of purchase in Tally. I am aware Tally has that option when adding purchase in Voucher mode. The problem is that Tally does not allow (as far as I know) to credit two separate parties in the purchase voucher. So this is what we are doing:

Cr Supplier Account        (Invoice Amount + Amount Paid to transporter directly)

Dr Purchase Account (exact item with the extra cost)

Dr IGST @ 18%

Next we pass a journal entry

Cr Transporter Account     (Amount Paid Directly to transporter)

Dr Supplier Account

Then we pass payment voucher to pay the Transporter.

Is this the best way to deal with this situation?