It is possible to parse VAKEY (100 chars) field to separated key fields manually, knowing the structure of each condition table (A004, A055, …).

But there much easier way: Function modules to generate VAKEY (a key for condition tables KONH – condition headers, KONP – condition details, KONM – quantity scale, KONW – value scale) and vice versa – parse key fields from given VAKEY knowing the condition table name.

DATA:
  ls_komg    TYPE komg,     " Allowed Fields for Condition Structures
  lv_vakey_1 TYPE vakey VALUE '106002B1050000 1097631S50',
  lv_vakey_2 TYPE vakey.

* 1. Get key fields for given VAKEY and condition table
CALL FUNCTION 'SD_CONDITION_KOMG_FILL'
  EXPORTING
    p_kotabnr = '005'   "table name is A005 (here we use '005')
    p_kvewe   = 'A'     "table name is A005 (here we use 'A')        
    p_vakey   = lv_vakey_1
  IMPORTING
    p_komg    = ls_komg.

* 2. Get VAKEY from given key fields and condition table
CALL FUNCTION 'SD_CONDITION_VAKEY_FILL'
  EXPORTING
    p_kotabnr = '005'
    p_kvewe   = 'A'
    p_komg    = ls_komg
  IMPORTING
    p_vakey   = lv_vakey_2.

* Just verify that generated VAKEY is equal to the original VAKEY
IF lv_vakey_1 = lv_vakey_2.
  WRITE 'OK'.

ENDIF.