A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
Put a 0 in an unused cell and copy it.
Select your 'numbers-with-an-apostrophe-prefix' and right-click, Paste Special.
On the Paste Special dialog, choose Paste, Values and Operation, Add then click OK.
BTW, if your 'numerical numbers' are longer than 15 digits, you will lose mathematical precision due to Excel's 15 significant digit floating point precision limitation. See Floating-point arithmetic may give inaccurate results in Excel.