Currently the implementation of Excel formulas within RSAT test case Excel artifacts looks to be very limited when it is about using "Saved variables". It would be great if we may use saved variables in any kind of Excel formulas and not be limited to a given kind of formulas and or given kind of data type. This might off course need refactoring the current implementation. See also support case for related information: 119043025000810 - Excel formula calculation using saved variables ({{global_value_date}} + 2