Need to create custom URL for affiliate because of adwords

We set up an entire campaign, launched it and within days of the launch one of our partners said they wanted to run adwords.

The problem is that the custom url we set up in the affiliate links, does not match the destination URL. We thought we’d be clever, but now we realize the marketing drawback.

Can someone suggest a workaround or third party plugin that will work and make sure the affiliates tracking info also gets forwarded.