If I understand the Wealth-Lab framework correctly (And I'm new to Wealth-Lab, so my understanding may be in error, so correct me if I'm wrong.), but there isn't a good way to access
multiple external symbols
simultaneously in order to perform the efficient frontier optimization problem you're referring to. Part of this has to do with the scoping design of Wealth-Lab where only one external symbol is accessible at a time and the fact that C# doesn't support multiple inheritance.
But efficient frontier optimization is an
important part of Modern Portfolio Theory (MPT), and it's actually used by Fidelity fund managers to asset allocate many of their managed funds so as to minimize turnover within them. (Understand, those in high tax brackets don't want to invest in funds that have high turnover.)
If you're into
heavy numerical analysis, or at least had a year course in linear algebra (That's the class you typically take sometime after first year calculus.) and have
lots of patience, then let me recommend MatLab to you. All the signal processing, image processing, and control engineers I know use it--it's a standard in the engineering field. In addition, you'll also need it's Financial Toolbox, which implements the efficient frontier paradigm. You do not need the Optimization Toolbox for this problem. You will need the DataFeed Toolbox, or some way to get raw DataSeries data into MatLab.
Go to this link
http://www.mathworks.com/help/finance/asset-allocation-and-portfolio-optimization.html and proceed to click on the links in the two examples at the bottom. They will walk you through setting up the problem. Honestly, there's a lot to learn here if you haven't used MatLab before (
much more so than learning Wealth-Lab), but if you're into numerical analysis, you won't mind.
If you really want to get into it, there's also a C++ code generator (sold separately) that will turn your MatLab macro files into C++ code you can compile and call as a Windows DLL library (say from Wealth-Lab). But you
cannot change the variable scoping design of Wealth-Lab, so it's
never going to be able to pass multiple external DataSeries symbols to the MatLab/C++ code that you compile. That's just not an option.