I think it's two separate questions.
To protect part of a spreadsheet:
1 - Use format / cells / protection and check locked or hidden. Make sure the other cells are not protected or hidden.
The protection is not in place yet. First you need...
2 - Tools/Protection/Protect-sheet or Protect-workbook
To allow someone to copy only the results and not the formula, I think you need to allow them to see only the results and not the formula. Put the formula in some part of the workbook which will later be hidden. In the cell the user will have access to, just add the value of that hidden cell to display it. Then hide that cell so the user can't get to it. I think this will work.
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