I need to alter this formula to allow the ability to input data, however when the worksheet is cleared (data deleted)I still need the formula to be in the selected cells. The data input could be any of the following E,R,W or the numeral 0 .

=IF('[Tomb MASTER.xlsx]DATA'!A5="","-",IF('[Tomb MASTER.xlsx]DATA'!A5="s","S"))

Greatly appreciate any help.