how to export an excel data into matlab with row header in between

I have very large data (100000 by 2 )which looks like the following:

                       *CN*
         10.598       1.890
         11.222      -5.369
        -10.256      11.235
         14.589      15.888 
           .           .
           .           .
                       *CN*      

         20.359      14.523 

          6.256       9.124
           .           .
           .           .

The 100000 column is divided into 35 parts by column header(CN)in the second column represent the number of column that follows ( for example the first CN is 10, the second is 25 and so on). My target is to multiply column one and column two and at last i have 100000 by 1 matrix including CN.

Could you please tell me how can i do that. I attached also sample file. Thanks.