Dim Rng As Range
Dim WorkRng As Range
On Error Resume Next

lRow = Range("U" & Rows.Count).End(xlUp).Row
Set MyRows = Range("U19:U" & lRow)
For Each cell In MyRows

splitVals = Split(cell.Value, ",")
    totalVals = UBound(splitVals)
    Range(Cells(cell.Row, ActiveCell.Column + 1), Cells(cell.Row, ActiveCell.Column + 1 + totalVals)).Value = splitVals
Next