Lock/protect cells to only except pasted values

Hi All, I was hoping someone could explain how I could set up a range of cells in a spreadsheet that do not allow any values that are typed into a cell, only those that are copied and pasted from another source.

It's for work and I need to have something in place for audit purposes to demonstrate that the data represented in the range is an exact copy of the source data and it's not possible for someone to manually type over it by mistake.

Thanks,
James