writing lags and lead with the symbolic toolbox

does anyone know how to write an equation with lags and leads using the symbolic toolbox? for example: E_t [ P_t+1] = Beta*P_t + Rho*C_t-1

[Walter Roberson]

There are different E functions for each time step??

"The t'th function E, applied to P indexed at (t+1), is beta times (P indexed at t) plus Rho times (C indexed at (t-1)" ??