I列に
=IF(ISNUMBER(MATCH(TRUE, ISNUMBER(SEARCH(","&D2&",", ","&$H$2:$H$9&",")), 0)), TEXTJOIN(",", TRUE, IF(ISNUMBER(SEARCH(","&D2&",", ","&$H$2:$H$9&",")), $D$2:$D$9, "")), "999999")
N3に
=IF(H2="", 0,H2)
N列End
=IF(ISNUMBER(MATCH("999999", I2:I9, 0)), TEXTJOIN(",", TRUE, IF(I2:I9="999999", D2:D9, "")), "")