SecondaryOrderID usage: Is this correct?

Imported from previous forum

Situation:
As an intermediary / execution system between the buy and sell side, we need to map the OrderID generated by the sell-side to the trade in our system. This mapping was intended to be used when we receive the DK from the buy-side which has the OrderID replayed back.

Possible Solution:
Populate the SecondaryOrderID(tag 198) en-route to the buy-side when passing thru our system with our internal key for the trade and have the buy-side replay it back. This way, we dont mess with the OrderID used by the sell-side (we dont even have to interpret it) and nor do we have to keep an internal mapping of OrderID to our trade key.

Question:
Is this solution appropriate - am I using the Tag in the correct sense?

Comments / critique appreciated!