Change Table values based on what it slicer value

I have the above table in Power BI. I need the 'Percent Value' column to be populated with a value based on a parameter selection, i.e. If I input 80 (%) I want the following to appear:

I cannot use a calculated column as the 'Percent Value' will need to change depending on the slicer (what if) selection. I don't know how to structure a measure as I cannot use the 'Gross Pay' value, it is loaded directly from an excel file and not available for use within a measure.

Any help greatly appreciated.