What do you mean by "open each cell"? xlsread() can return two cell arrays and one numerical array
[numericalMatrix, cellArrayStrings, cellArrayRaw] = xlsread(filename);
When you say "cell" do you mean like a MATLAB cell like is described in the FAQ http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F, or do you mean a cell like what Excel calles cells but MATLAB calls elements. And again, how do you "open" it?
How did you get that display? Did you just put val by itself on the line of code or in the command window? Or you did something else to generate it?