how can I change the Excel file format from matlab

Hello, I try to change a .xls file format in to .xlsx format.

Answer 1

[Azzi Abdelmalek]

[~,~,im]= xlsread('file.xls');
xlswrite('file.xlsx',im)

[Gabriela]

But what if I have 600 sheets in this Excel,..how can I do it?

[Image Analyst]

Use ActiveX programming - unless you're prepared to wait a very very long time. See my attached demo.