The productivity of parallel programming has become essential with the rapid advance of multi-core and many-core processors. Especially, the programming environment of economical small or middle scale clusters using accelerators must be improved. Here, a tool for extending a parallel program for a single Cell Broadband Engine (Cell/B.E.) to that for small scale clusters with Cell/B.E. is proposed. Since the Cell APIs must be called in a certain order, the tool inserts directive and MPI library calls automatically. The developed tool successfully extends an application using Monte-Carlo method for Cell/B.E. clusters. When 16 nodes each of which uses 8 SPE are used, the performance of automatically generated code was 0.74 times that of manually optimized code. Although the proposed tool has a room of improvement on the distribution of job between PPE and SPE, it can generate the practical program only with a simple configuration file.