Actually, they just need to be on different lines, like this:
IF RNUM==1 THEN
GOTO @ENPTY1
ELSEIF RNUM==2 THEN
GOTO @DEAD6
ENDIF
Basically, ELSEIF requires that you use a multi-line IF statement, which starts with the IF, contains the actions on the next lines, and ends with ENDIF.
1そうだね プレイ済み