you can open a report as excel without displaying in alv using the below code:
CALL METHOD cl_gui_frontend_services=>execute
EXPORTING
document = c_file
operation = 'OPEN'
EXCEPTIONS
cntl_error = 1
error_no_gui = 2
bad_parameter = 3
file_not_found = 4
path_not_found = 5
file_extension_unknown = 6
error_execute_failed = 7
synchronous_failed = 8
not_supported_by_gui = 9
others = 10.
IF sy-subrc <> 0.
* Do Nothing
ENDIF.