"I'm using an old version of Keil (uVision 1) and I didn't seen any 'code browser'. As I had already downloaded the evaluation version of uVision 2, I would check there but I didn't founded the option too."

I'm sorry, Keil actually call it the "Source Browser"

The Source Browser is described on p69 of the Getting Started with µVision2 Manual (02.2001).
(the full manual set is included in PDF with the eval download - this is GS51.PDF)

The sorting works as in explorer - click on a column heading to sort by that column; click again to reverse the sort order.