A

DATA itab LIKE SORTED TABLE OF line WITH UNIQUE KEY table_line.

DATA output TYPE TABLE OF string WITH EMPTY KEY.

DATA num TYPE i VALUE 400.
DATA dref TYPE REF TO i.
DATA cond TYPE string.

itab = VALUE #( FOR j = 1 UNTIL j > 30
                  ( col1 = j
                    col2 = j ** 2 ) ).

dref = REF #( num ).

LOOP AT itab INTO line FROM 10 TO 25 WHERE col2 > dref->*.
  APPEND CONV string( line-col2 ) TO output.
ENDLOOP.

APPEND INITIAL LINE TO output.

cond = 'col2 > dref->*'.

LOOP AT itab INTO line FROM 10 TO 25 WHERE (cond).
  APPEND CONV string( line-col2 ) TO output.
ENDLOOP.

cl_demo_output=>display_data( output ).