tdf106013 Add-In functions that are also Excel2013 OOXML functions

Hi Eike,

I'm sort of stuck with tdf106013.

There is a group of Add-In functions that were newly defined in Excel 
2013 (IMCOSH, IMCOT, IMCSC, IMCSCH, IMSEC, IMSECH, IMSINH and IMTAN, 
I'll call them IMxx).

In Calc these functions are defined in scaddins and also mentioned in 
sc/source/filter/oox/formulabase.cxx in saFuncTable2013[].


The problem is that the IMxx functions saved as xlsx by Calc won't open 
correctly by Excel and vice versa.

Calc writes the IMxx functions in xlsx as =IMxx(...), just as on ods.

Excel writes the IMxx functions in xlsx as =_xlfn.IMxx(...), and in ods 
as =IMxx(...).

The other Add-In functions are written by both Calc and Excel as 
=FUNCTIONNAME(...).


When I define the IMxx functions as regular functions, there are written 
as =_xlfn.IMxx(...) in xlsx, but when written to xls, they give problems 
when opening in Excel.


Any suggestions for a solution?

Currently I haven't got further than breaking xls-compatibility and 
starting OOXML-compatibility.


Winfried