Hola,
Yo utilizo la clase cl_gui_frontend_servicesy el metodo file_open_dialog para seleccionar el archivo excel de la PC.
ejemplo:
call method cl_gui_frontend_services=>file_open_dialog
exporting
window_title = l_title
default_filename = l_def_file
file_filter = ' '
initial_directory = 'C:\'
changing
file_table = lt_files
rc = l_subrc
exceptions
file_open_dialog_failed = 1
cntl_error = 2
error_no_gui = 3
others = 4.