>1. Given a non empty memory block of known total length
>2. Given the data in this memory block are LONGs that actually form a 
>2D-array
>3. Given the number of columns of the array that may _vary_ (not a constant)
>4. How can the data be accessed through a proper 2D-array?

If there is enough memory to do it, I'd have a "maximum sized" 2D array 
defined separately, and blockmove each column of the implied array into 
the appropriate locations.

Bill