Not sure you want to get into this - the general form could look like:

Dim darrMySimulationData() As Double
Dim i As Long, j As Long

ReDim darrMySimulationData(1 To 1000, 1 To 60)

j = 1
For i = LBound(darrMySimulationData) To UBound(darrMySimulationData)
darrMySimulationData(i, j) = 1 ' Your func here
Next i

For j = LBound(darrMySimulationData, 2) + 1 To UBound(darrMySimulationData, 2)
For i = LBound(darrMySimulationData) To UBound(darrMySimulationData)
darrMySimulationData(i, j) = darrMySimulationData(i, 1) ' Your
func here
Next i
Next j


However, as far as I know you cant use the rand function in VBA (but there
are several VBA implementations if you google for them).