Then try this…
Create a loop inside the excel application scope and break the data in chunks of 20000 and use append range
to get data in chunks of 20000 use dt.AsEnumerable.Skip(Cint(20000*counter)).Take(20000)
Create a counter variable and assign it to the index variable in for loop… in the for loop in Argument use Enumerable.Range(0,Cint(Dt.Rowcount/20000)+1).ToArray
use append range with the above given chunks formula
Hope this helps
cheers