VBA is unlikely to be sufficient, Matlab and R are good picks, depending on the firm SQL might help. C++ is a strong contender - though native Java is okish and if speed really really matters embedded solutions and parallelization are available… sorry got caried away… People are known to have written HFT solutions in VB6…
Most likely, however, VBA would provide glue to make the management ready Excel sheets and Power Point slides work with _the real stuff_. SAS and SPSS are not unhread of either but I guess are much less frequently used. In any case, the tools do not matter nearly as much as you being able to be proficient in anyone of them as to do the job.
Chances are, since derivative risk management is so heavily quantitative, that you already are proficient with some of the tools. So you should be fine, even if your math background only exposed you to tools such as Mathematica or Maple.
You are smart, you will learn the tools as and once you need them. Take a few ideas off the Risk Magazine Cutting Edge section or any of the Risk journals (see http://papers.ssrn.com for free republications) and implement them in a tool you like best.
IMO its all about algorithms (for Quant jobs)…if u are good at those…u should be fine irrespective u know a paticular programming language or not…and by good i meant really…really…nerdy and good