How do you protect multiple sheets while only allowing users to select unlocked cells?

I am aware that Excel does not support this function unless you write and run a macro. I have found the code to protect multiple sheets at the same time with a password, but it allows users to manipulate any cell they desire. I have a lot of complex formulas contained on each worksheet and I don't want users to manipulate locked cells, just unlocked ones. I am not worried about the users finding and using the password to unprotect (I highly doubt any of them know what VBA even is, let alone edit the macro) Following is the code I used is found below. Please help, I was never good at writing VBA code.

Sub ProtectAllSheets()

For Each ws In ActiveWorkbook.Worksheets

ws.Protect Password:="secret123"

Next ws

MsgBox "All Worksheets Protected"

End Sub

Sub UnProtectAllSheets()

For Each ws In ActiveWorkbook.Worksheets

ws.Unprotect Password:="secret123"

Next ws

MsgBox "All Worksheets Unlocked"

End Sub