How to use multiple input in arima(2,0,1) (ARMA) model? And How to and what to conclude from its result if i am using it for forecast?

I want to forecast the price of the electrical price on the basis of the electrical load. i have data of both the variables at specific time intervals. So how can i use the ARMA model to forecast using this two variables. I have done using one variable but two, it doesn't accept. After using one variable and using the fit tool for estimation, i am not understanding what the output want to say. So can u please help me to understand?

[Triveni]

we don't have any magic stick...What are you thinking??...You have to show your programming problem...what are you trying to do...whatever you have tried...??? ARMA Model normally use to solve time series...?tell here whats your problem with programming.

http://in.mathworks.com/help/econ/arma-model.html