'.',⍨¨ ','(≠⊆⊢)'abc,123,X'   ⍝ [1] Do the split: ','(≠⊆⊢)'abc,123,X'; [2] append the periods: '.',⍨¨
 abc.  123.  X.                   ⍝ 3 strings (char vectors), each with a period at the end.