AWGN channel simulation with a binary asymmetric channel

Hi, I've looked around quite a bit, but can't get a solution for simulating a binary asymmetric channel. I am supposed to simulate a BSC (binary symmetric channel) as well as a asymmetric channel for probability of error 0.001.

I managed to do the binary symmetric simulation (By generating uniformly distributed random data set, worked out the SNR and used the "awgn(A,SNRdB)" function and mapped back to binary symbols with soft detection, and compared the sent and received mapped symbols to determine the error probability)

So well, I still have to do the asymmetric channel simulation, but can't find a lead to accomplish this with matlab.

Will appreciate any links to implementations solving this problem