>You could pass an additional parameter from one method to another, to indicate whether the other parameters were passed by reference or by value. If you need to do this with several parameters, you can pass a string: "0010" ("third parameter was passed by value - all others by reference"). Default this to "reference" for all if no fifth parameter was passed - this seems to be safest.

Thanks Hilmar, this might be way, but for my specific problem, I think my workaround is the better one, since the caller can can pass anything he likes and it still works. Please see my reply to Gerald regarding more details on what I'm doing.

Thanks,
Armin