It's not supposed to matter at all, and I only know of one app that doesn't like lowercase - which most systems generate.
But ... it's not that difficult to do:
c# - utf-8 in uppercase? - Stack Overflow[
^] - the code is C#, but it should be pretty simple to convert. Ifg you need it, online converters exist:
Code Converter C# to VB and VB to C# – Telerik[
^] which may do most of it for you.