Integral of bivariate normal distribution & find solution

Hello.

Can anyone teach me how to figure out following problem.

f(B,C) is pdf of bivariate normal distribution.
mu=[1.5 30]; (where mu_b=1.5, mu_c=30) 
sigma=[0.09 0.5; 0.5 100];

Using these information, I first want to calculate expected value of C under bivariate normal distribution.

TC = TA*E(C) = TA*doubleintegral(C*f(B,C))dBdC --eq.(1)

TA = 920;

-> C_lowerbound = 0

-> C_upperbound = +inf

Infortant thing is that the lower bound of B is functional form.

-> B_lowerbound = C*lamda_star , where lambda_star = 0.06

-> B_upperbound = +Inf

At second,in equation (1) above, if TC = 5000, and lambda_star is unknown, how to solve the lambda_star? Expected boundary of lambda_star is from zero to one. (lambda_star=[0,1])

I am totally beginner of Matlab. If anyone can teach me how to deal with this problem, it would be very appreciated.