I just did a quick macro record

Range("D8").Select
ActiveCell.FormulaR1C1 = "1,2,3,4"
Range("D8").Select
Selection.TextToColumns Destination:=Range("D8"), DataType:=xlDelimited, _
TextQualifier:=xlDoubleQuote, ConsecutiveDelimiter:=False, Tab:=True, _
Semicolon:=False, Comma:=True, Space:=False, Other:=False, _
FieldInfo :=Array(Array(1, 1), Array(2, 1), Array(3, 1), Array(4, 1)),
TrailingMinusNumbers:= True