>>Don't you have a French keyboard ?
>
>What do you mean?

I think I mean I was talking through my hat :-}

I'm not clear how you are building the xml but would it be possible to create it using ISO-8859-1 and then use Encoding.Convert to get a UTF-8 representation ?

https://msdn.microsoft.com/en-us/library/kdcak6ye(v=vs.110).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-2

Disclaimer : Never tried this........