Reading from many columns of an excel sheet

I tried xlsread() but it does not work.I am passing A to a function which will process the data. Please help

A = xlsread('C:\File.xls','Marks','A1:D10'); [rows cols] = size(A); for m = 1:rows for n = 1:cols B(m,n)=A(m,n); B(m,n)= Grades(A(m,n)); end end xlswrite('C:\File.xls',B,'Grades','A1:D10');

[per isakson]

Any errror message?