Wiseass (but true) answer:
Don't bother. VB is an utter waste of time and will ultimatly just slow down the progress of your coding skill. It does so many things back-asswards from the norm, if you ever want to advance to another language that doesn't completely suck, you'll have to 'unlearn' a lot of the stuff VB taught you.
C's syntax is actually very simple (I'd say even simpler than VB). The only thing that's 'hard' about making programs in C is working with the API... but the thing is... all serious VB apps work with the API anyway because the VB substitutions are stupid and slow. Not to mention so many other languages are based on (or at least are remarkably similar to) C/C++... including Java, Delphi, C#, even PHP. So by taking the 2 extra days it takes to learn C instead of VB, you'll have a foot in the door on whatever language you decide to move to next.