We have implemented molecular dynamics (MD) generated sputtering data in the Monte Carlo impurity transport code ERO. The data set covers D bombardment of BeC, Be2C, Be2W, W2C and WC that are potentially formed on divertor targets in machines operating with an ITER-like wall. We see that intermediate compounds can have a sputtering yield different from that estimated from a homogeneous mixture, especially in the case of carbide formation with its characteristic strong bonding. At other stoichiometries, grain formation affect the yields. We also observe preferential sputtering of the lighter elements and molecular release. A linear interpolation method is proposed for the evaluation of the sputtering behaviour of any ternary Be/C/W composition.