I\'m working with a dynamic array in Excel VBA. The number of columns (m) is fixed, however, I do not know how many rows (n) will be required.
The help documents st
If you are developer - what is the difference between rows and columns? Using array(N, 2) (if you have 2 columns) is the same as array(2, N) - for which you can
ReDim Preserve arr(1 to 2, 1 to N+1). 
And the difference for you (as developer) will be to put the variable from the cycle in second place, instead of the first one:
N = ubound(arr)
FOR i=1 to N
    GetColumn1Value = arr(1, i)
    GetColumn2Value = arr(2, i)
NEXT i
Or you want this:
N = ubound(arr)
FOR i=1 to N
    GetColumn1Value = arr(i, 1)
    GetColumn2Value = arr(i, 2)
NEXT i
What is the difference?