В последних выпусках 7.50+ вы можете выбрать один выбор без циклического выбора SELECT:
SELECT ks~kostl, ks~datbi, ks~name1, ks~kosar, ks~verak, pc~prctr, pc~name3, pc~name4,
CASE SUBSTRING( ks~kostl, 1, 1 )
WHEN '1' THEN 'Washington'
END AS location
FROM csks AS ks
INNER JOIN cepc AS pc
ON ks~prctr = pc~prctr AND ks~kokrs = pc~kokrs
WHERE ks~bukrs = cocode AND
ks~kokrs = cntrarea AND
ks~datbi > d1
INTO TABLE @DATA(it_itab)
UP TO 100 ROWS.