You can't mix languages within a single project, although you can reference Assemblies regardless of what language they were written in.
But you can use automated translators to convert between them:
Code Converter[
^] isn;t too bad. Be aware that it may not get it right, so you should really understand both languages when you test this, and be aware that unless the "source" of that code is targeting the same environment your code is that may not work at all.
Generally speaking, you are better off writing your own code than relying on code you found on the internet and translating it.