Created Issue: Data Validation [8628]

I've been searching for a solution to my issue for a while so if I have overlooked a solution, please forgive me.

I am trying to set data validation on a column and simply want to pass a comma delimited list for validation. I am attempting to recreate an Excel report that has this functionality embedded.

```
Dim dataV As ClosedXML.Excel.IXLDataValidation = Nothing
dataV = ws.Column(3).AsRange().SetDataValidation()
dataV.List("CD, SD, MW")
dataV.IgnoreBlanks = True
dataV.InCellDropdown = True
dataV.ShowInputMessage = True
dataV.ShowErrorMessage = True
dataV.ErrorStyle = ClosedXML.Excel.XLErrorStyle.Stop
```

The issue is that ClosedXML is generating a formula (with =) in front of the string (=CD, SD, MW). Excel doesn't like this. How can I generate my list without the "="?

Great product BTW...Thanks!

Kelly