Hi Fredrik,
I check the code of Z-program and find below code:
CALL FUNCTION 'WS_DOWNLOAD'
EXPORTING
FILENAME = 'C:\chditem'
FILETYPE = 'ASC'
TABLES
DATA_TAB = DOWNLOADDATA.
REFRESH DOWNLOADDATA.
CALL FUNCTION 'WS_DOWNLOAD'
EXPORTING
FILENAME = 'C:\chdend.tmp'
FILETYPE = 'ASC'
TABLES
DATA_TAB = DOWNLOADDATA.