You could try and search the Internet for C# -> VB translators. If I remember right, there are tools out there that can translate C# code to VB, i.e. to a language that you're fluent in.
Anyway, the most complex part of the code (not REALLY complex, btw) is the decoding of the device specific payloads from ANT+ messages. Reading the device profiles helps you to accomplish this (and covers other aspects like setting up the correct ANT+ communication parameters when setting up your app to receive data from different ANT+ sensors. Device profiles can be found in the "Downloads" part of this web site - when you're an ANT adoptor.
Cheers,
OMB