=+Sheet1!A1+Sheet1!B1+Sheet1!C1 macro to convert all linked ref to Values

I want a macro to convert all linked references to individual values with in the cell. A1=10, B1=15, C1=5 D1=+Sheet1!A1+Sheet1!B1+Sheet1!C1

I want D1 to become =10+15+5 when you click within cell. D1 will show 30 when viewing as it does now. I want the macro to do this to all cells in worksheet that reference other cells

how do you attach file