Your string looks like it's encoded as UTF-8, which Windows doesn't handle.
You'll need to convert it to UTF-16 and ensure that you're calling the wide version of SetDlgItemText
, either by changing your project's character set option to Use Unicode Character Set
or specifying SetDlgItemTextW
.
You can convert your string from UTF-8 to UTF-16 with the MultiByteToWideChar function.