Combine elements in total compensation statement

Summary: Is there anyway to have 2 elements make up a compensation item for a compensation category?

For example we have 401K element for our salaried workers, and then another 401k element for our hourly workers. Same for some benefits elements. I would like to add the 2 totals together for the compensation item (within the category). I don't want 2 lines to appear if a worker goes from hourly to salaried.

I would also like to add in retro to elements where there is retro, and not have a separate item for retros.

If the answer is a fast formula, do you have an example I can use? If I had one example, I can write the 50 or so others that I need to.