So you have a list of enum values and you need to convert it to a single string separated by some character.

To demonstrate this we need an enumerated type:

public enum test{
    No,
    Yes,
    Maybe,
}

and a list of enum values:

var n = new List();
n.Add(test.Yes);
n.Add(test.Maybe);

To get the character delimited string we need to convert the list to an array, add a bit of Linq, and use string.Join to finally concatenate the values:

string.Join(" - ", n.Select(s => s.ToString()).ToArray())

The first parameter passed to the Join method is the separator between each list item.

Voila!