Try to copy file with CopyFile API #12708. It seems to respect destination file name case.

DECLARE INTEGER CopyFile IN KERNEL32.DLL ;
   STRING SourceFileName, ;
   STRING DestFileName, ;
   INTEGER bFailIfExists
IF CopyFile("orders.pdf", "ABCDEFGH-O.PDF", 0) > 0
  * File copied
ELSE
  * File isn't copied
ENDIF

>My program is creating a new file by using the COPY FILE orders.pdf TO ABCDEFGH-O.PDF. Using the DIR command in DOS shows a file name of ABCDEF~1.PDF 5,560 12-30-02 5:54p abcdefgh-o.pdf. The new file is then used as an attachment to an email. When the email receiver gets his email, the file name is all in lower case. It is apparent that outlook is using the long name as it sends it. I am unable to find out how to create both the DOS short name and long name in CAPS.
>
>Would appreciate any guidance from some one and I thank you in advance for any help.