Data: I_SUM LIKE ZTAXREGT OCCURS 0 WITH HEADER LINE.
DATA:
    FNAME(30).
FIELD-SYMBOLS:
<SUM> LIKE I_SUM-HSL01,
<REP_SUM> LIKE I_SUM-HSL01.
.....
DATA: begin of itab2 occurs 0,
      HIER_KEY like  J_3RFTAX_OBJSEL-HIER_KEY,
      NODE_CODE like  J_3RFTAX_OBJSEL-NODE_CODE,
      RTAXOBJ LIKE J_3RFTAX_OBJSEL-LOW,
      RTAXOBJ_HIGH like J_3RFTAX_OBJSEL-HIGH,
      LOW like J_3RFTAX_OBJSEL-LOW,
      HIGH like J_3RFTAX_OBJSEL-HIGH,
      HSL like ZTAXREGT-HSLVT,
      LINENUM like  J_3RFTAX_OBJSEL-LINENUM.
DATA: end of itab2.
....
SELECT  SUM( HSL01 ) AS HSL01 SUM( HSL02 ) AS HSL02
         SUM( HSL03 ) AS HSL03 SUM( HSL04 ) AS HSL04
         SUM( HSL05 ) AS HSL05 SUM( HSL06 ) AS HSL06
         SUM( HSL07 ) AS HSL07 SUM( HSL08 ) AS HSL08
         SUM( HSL09 ) AS HSL09 SUM( HSL10 ) AS HSL10
         SUM( HSL11 ) AS HSL11 SUM( HSL12 ) AS HSL12
FROM ZTAXREGT
    INTO CORRESPONDING FIELDS OF table I_SUM
    WHERE RLDNR = 'JS'
    AND RRCTY = '0'
    AND RVERS = '004'
    AND RYEAR = RYEAR
    AND RBUKRS = RBUKRS
    AND RTAXOBJ = itab2-RTAXOBJ.
"динамически определить ссылку на поле с суммой за период
    CONCATENATE 'I_SUM-HSL' POPER+1(2) INTO FNAME.
    ASSIGN (FNAME) TO <SUM>.
    IF SY-SUBRC = 0.
      I_SUM-HSL01 = <SUM>.
    ENDIF.
    IF <SUM> IS ASSIGNED.
    ITAB2-HSL = <SUM>  .
    ENDIF.