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.
I know of no other way to do what you want - specifically, using code only in the called method.
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)