I would like to be able to have a Excel 2016 spreadsheet open on PC, it will have a slider and a couple of buttons and when selected by mouse do their thing. Then as an option I would like to use an Android phone with bluetooth (or WiFi) to replicate screen on PC and can use touch to activate button or slider on PC.
Excel for Android enables you to open Excel files but it does not allow the controls you described. You'll have to test what types of "buttons" (slicers come to mind) may do the trick for you. Alternatively, you could use teamviewer to connect to your desktop computer from your phone.