New Post: Validation of cell using fixed List of values

After experiencing a similar issue and after much unsuccessful Googling, with the aid of the Microsoft Open XML SDK managed to get to the bottom of this one and the syntax required where you do not want to use ranges:

workSheet.Cell(rowIndex, 1).DataValidation.Value = "\"yes,no\"";

i.e. Comma separated list but requires additional quotes surrounding it to avoid being treated as a formula.

Hope this helps others.

Marie