>You can use Win API to preserve destination file name case. See Re: Rename a file long file name from lower to upper case Message #801674

Well, based on this, this is how I succeeded to achieve that:

DECLARE INTEGER CopyFile IN KERNEL32.DLL ;
   STRING SourceFileName, ;
   STRING DestFileName, ;
   INTEGER bFailIfExists

ADIR(laFile,'*.*','',1)
FOR lnCompteur=1 TO ALEN(laFile,1)
   lcFile=laFile[lnCompteur,1]
   lcFileNew=UPPER(SUBSTR(lcFile,1,1))+SUBSTR(lcFile,2)
   RENAME laFile[lnCompteur,1] TO (lcFileNew+'a')
   CopyFile(laFile[lnCompteur,1]+'a',lcFileNew,0)
NEXT

Then, I removed the temporary files which have been renamed in order to keep the same name.

Thanks