how dcast melted data winto a table with header and sub-header?

Question

I have Input data like the one below and I want to know if there is any way to reshape it into an Excel format with a header and sub-header.

Input:

Cons   rep   name   value
10     N=1     A      12
10     N=2     A      13
10     N=1     B      10
10     N=2     B      11
12     N=1     A      23
12     N=2     A      24
12     N=1     B      23
12     N=2     B      21

OutPut:

          A          B
      N=1  N=2    N=1  N=2  
10    12   13     10    11
12    23   24     23    21

I could get the below results using the dcast() function, but I want to know if there is a way to separate N=1 and N=2 as sub-header of A and B.

   A_N1 A_N2 B_N1 B_N2
10   12   13   10   11
12   23   24   23   21