Payroll Calculation - Additional Wages to be included in W-2 box 1

We are a union shop and we are trying to simplify our pay groups.  Right now we have thousands of pay groups because we have the base union pay group but we elect as a company to pay employees more than their dispatch.  For the last 10 years we have created new pay groups to do this.  Some might say that we should just manually adjust the wage in the employee record, but unfortunately with SFO importing hours it defaults the time entry to the wage of the pay group and disregards the changed rate in the employee profile, so that's been a no-go.  Every 6 months when the union rates change we have to go through and modify thousands of pay groups.  It's getting tiring and the number only continues to grow. 

So, I had the bright idea to add an internal adjustment calculation.  In my testing this works fabulously and everything reports correctly on the GL's, it's taxed correctly and the amount to the employee is correct.  The problem is the W-2.  I have to give this calculation a box and code for the W-2, but it's just wages and entering "Box 1" doesn't work.  It also doesn't show up on the employee pay stub as YTD wages.  The number that shows up there is the base rate on the dispatch, not the base rate + what we elect to pay them extra.

Is this even possible?  It's driving me nuts and any help would be appreciated!

Here's an example of what works but doesn't report on the W-2 correctly.