What I did was just created new spreadsheet just for the S-Curve data.
I manually populated the Scurve Date column by weekly and calculate the Planned End Date, Forecast End Date and Actual End Date that are before before the S-Curve Date. This way we can know the progress of the project. for the percentage, just need to divide the number with the total activities throughout the project duration.
Hope this helps those who wants to create S-Curve 🙂