Try to access the ERFC-function with a macro, for example

function MYERFC (byval z) as double
DIM oFunktion as variant
oFunktion = createUnoService("com.sun.star.sheet.FunctionAccess")
Dim aArgumente(0) As Variant
dim erfcresult as double
aArgumente(0)=z
erfcresult = oFunktion.callFunction( "ERFC", aArgumente() )
MYERFC=erfcresult
end function

This works fine in an English UI. Now open the same document in a German UI. You
will get an error "comm.sun.star.container.NoSuchElementException".

For the normal functions is works as expected, that the function in the
statement is always English. For the Addin function 'Erfc' the statement needs
the localized name.

I consider this a bug, because the behavior is different and it makes it
impossible to distribute such macros.