How to change two variables when a data table doesn't work

Hi everyone

I have a (read: extremely complicated) spreadsheet which performs a complex valuation calculation. There are a whole host of inputs, but there are two main inputs which I want to “flex”:
1. Cost of capital
2. Capital expenditure

There are effectively three tabs (of the 20+ tabs) on the worksheet that I’m interested in:

First: Calculates the cost of capital
Second: Has an input cell for the capital expenditure
Third: A valuation number, which is based on the cost of capital and the capital expenditure (both of which are input per the above), as well as many other inputs all in other parts of the spreadsheet

I have a list of cost of capital figures (5 figures) and a list of capital expenditure amounts (5 amounts). This gives a total of 5 x 5 = 25 scenarios.

I want to build a summary that says:

“Hey Excel, I’m going to give you a cost of capital figure. I want you to input that into a cell on tab X of this valuation spreadsheet. And then I want to give you a capital expenditure figure. I want you to input that into a cell on tab Y of the spreadsheet. And then look at tab Z – see that figure that’s calculated? I want you to copy that into this table here.”

I know that a data table could be used for this. But the problem is there is no easy formula that links the cost of capital and capital expenditure (there are simply too many links and formulas in the spreadsheet for me to easily get a formula for the valuation number that includes the cost of capital and capital expenditure).

Is this even possible to do? If someone could even point me in the right direction as to what formula (or what would form the base of a macro) to use, that would be much appreciated.

Thanks so much!