It's not how I would do it.
I would use a dedicated phone number for this specific campaign. That way, you can track how many leads or sales are generated because of it.
It may take a month or two of "flying blind" before you have useful metrics, but when you do, then you can return to AdWords and adjust your efforts based on your ROI.
If your client or team can't supply you with this information, then there's little you can do about it and it will cost them.