Ok, so I know in TI you can take an Alias and figure out what the original element is using the DimensionElementPrincipalName...
What I wanted to know is if there is a similar function that can be used in Excel Worksheets, or maybe some workarounds using existing tm1 formulas...?
Another way may be to use the internal ALL subset e.g. I have a month dimension with an alias of 1 for Jan, 2 for Feb etc. If I want to return Jan (Principal) then I can do: