What if parameter and Analyze in Excel

Hi All

So I have a Power BI Report with a number of sliders with 'What If Parameters' to influence the figures in my data. 

For example; my business development app has a figure for revenue that I apply to reduce the figure by say 90% to give a true indication of future revenue based on our win rates. (So, leads we win 1 in 10)...So if my lead values are a total of £100M, I want £10M to come through). I have a measure for this called 'Factored Revenue'.

When I Analyze in Excel, these values are not coming into the data model ready for additional analysis.

Is there a way I can bring that 'default value' through rather than hard wire them in?