sorting a cell - with respect to its name

I have a cell which is sized 5x18. i made it using S = struct2cell(dir('*.mp3'));

I was going through http://www.mathworks.com/matlabcentral/fileexchange/10959-sortnat-natural-order-sort/content/sort_nat.m which is exactly the sort I need. I am finding it difficult to implement this for the cell S.

S(:,1)='fullrec Section 1.mp3' '27-Jul-2012 23:31:05' [ 3146813] [ 0] [7.3508e+005]

I would need to sort this S with respect to the names ( the first row). ie. *Section 2 should come after *Section 1 and NOT *Section 10

kindly help