how can i set a cell or column value to accept only numeric
data with the restrition of 16 digit length ???
It is unclear from your post whether you want exactly 16 digits to be
entered or a maximum of 16 digits to be entered. The formula below assumes
the maximum of 16 digits (change the <= to = for exactly 16 digits).
Select the cell, cells or entire column (as appropriate), click
Data/DataValidation on Excel's menu bar, change the Allow drop-down to
Custom and use this formula in Formula field...
=AND(LEN(A1)<=16,ISNUMBER(A1))
Change the A1 reference to the address of the first cell in the range you
have selected.
Rick