Pricing for the build-in Portfolio System

Lets consider the following portfolio:

Barrier = instbarrier('call', [100; 90], 'May-10-2013', 'Aug-09-2013', 0, 'do', 50, 0);
Portf   = instadd(Barrier, 'OptStock', 'call', 85, 'May-10-2013', 'Aug-09-2013', 0);
instdisp(Portf)

consisting of two barrier options and one regular call option. I have three questions:

1) Does the portfolio system in MATLAB allow me to specify some underlying asset in order to get the price of this portfolio?

2a) If so, is there also any build-in function to perform a Value-At-Risk calculation on this portfolio based on historic data of the underlying? I have already found the function portvrisk, but it does not seem applicable here.

2b) If not, then I am wondering (and this is not meant in any derogatory way!) whether the portfolio system is just a mere list of placeholders, i.e. it can store data on various products but does not actually interact with them?

I have tried looking at the MATLAB documentation and contacted Google Search, but I have not been successful. Any help would be appreciated.