Leave it as a number. Modify the cultural information in the stream and it will be displayed accordingly without the need for conversion.
eg.
Thread.CurrentThread.CurrentCulture = New CultureInfo("se-SE") Thread.CurrentThread.CurrentUICulture = Thread.CurrentThread.CurrentCulture
Never try to format numbers or dates in strings, or you will be on your way to hell.
UPDATE: John makes you think about the comments, you will find out whether this applies to your situation or not.
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