Hi Suman,
try to use 1503 codepage. On my project we use it like this:
CALLFUNCTION'GUI_DOWNLOAD'
EXPORTING
filename = lv_path
filetype = 'ASC'
codepage = '1503'
TABLES
data_tab = lt_tax_decl
EXCEPTIONS
file_write_error = 1
no_batch = 2
gui_refuse_filetransfer = 3
invalid_type = 4
no_authority = 5
unknown_error = 6
header_not_allowed = 7
separator_not_allowed = 8
filesize_not_allowed = 9
header_too_long = 10
dp_error_create = 11
dp_error_send = 12
dp_error_write = 13
unknown_dp_error = 14
access_denied = 15
dp_out_of_memory = 16
disk_full = 17
dp_timeout = 18
file_not_found = 19
dataprovider_exception = 20
control_flush_error = 21
OTHERS = 22.
ABAP source code in this document was coloured using the ABAP code lighter for SCN.
Best regards,
George Shlyahov