I had the requirement to write a function, which would be embedded in a cell
that could modify the values of other cells in the same worksheet. However,
the function kept returning the #Value error. I traced through the function
using Msgbox and established that the error was being caused the moment the
function tried to modify a foreign cell. After some experimentation it
appears that, just as Excel's own built-in functions only return a value to
the cell in which it is embedded and they have no constructs to modify the
contents of other cells, there must be a scope limit on user functions that
prevents a user defined function from modifing any cell but the one in which
it is embedded.

I have since found a work-around to this problem using a few programs tricks
and now the same code that caused the error works correctly, modifying other
cells. However, I would still like to know if anyone: has some familiarity
with this issue, can confirm that there is a scope limit in user defined
functions; and knows of a way to change that property to remove the scope
limit?

Thanks