Excel - Creating a Range of Output based on changing value of a cell. This ain't a table table quest

The spreadsheet I have calculates an XIRR on a stream of cash flows. Those cash flows change when I alter an assumption the spreadsheet. Would I'd like see is the XIRR when I change that specific input variable across a range of values. In short when I change the input the cash flows change and hence the XIRR value changes. The input being varied is not directly embedded in XIRR function so a table does not work. 

Solutions?