Loop through all sheets and copy and paste values for specific formula

Good morning all,

I am trying to write a macro that loops through all the sheets in an active workbook and looks for formulas starting with GXL [i.e. =GXL() or =-GXL()] and replaces the formula with the value for that cell. My current macro doesn't work so I am trying to build it from scratch and hoping someone has done this in the past.

could you send a sample with the input data and the expected result? It would be easier to write the macro