formatting a new char string

How do I format the VB.NET code below into a C# string?  I will be using the comma in a list for sending an email.  Your help is needed!
Dim Fromstr As String
Dim comma(0) As Char
comma(0) = ","
When I convert the code to c# I get the following error message:
Error: The Left-hand side of an assignment must be a variable, property or indexer
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