SET SAFETY OFF
I follow your advice, however it doesn't work. SO I attach my program and see what you can give me some idea about that.

******** Source code **********

line = 1
l_string = space(134)

store fopen(CHK_PATH) to file_handle
store fseek(file_handle,0,2) to ifp_size
store fseek(file_handle,0) to ifp_top

set device to print
set printer to &OUTPUT

do while .not. feof(file_handle)
l_string = fgets(file_handle,ifp_size)
if .not. empty(l_string) .and. rep_type = "S"
line_code = substr(l_string,1,3)
feed_code = substr(l_string,4,1)
if .not. empty(line_code)
line = val(line_code)
else
line = line + val(feed_code)
endif
prn_line = 0
do while prn_line < line
?
prn_line = prn_line + 1
enddo
* @ line, 0 say substr(l_string,5,134)
? substr(l_string,5,134)
else
if .not. feof(file_handle)
?
* line = line + 1
? substr(l_string,1,134)
* @ line, 0 say substr(l_string,1,134)
endif
endif
enddo

set print to
set device to screen
=fclose(file_handle)

*********** End of program *************

Thanks a lot!!