A wide range of scientific computing applications still use algorithms provided by large old code or libraries, that rarely make profit from multiple cores architectures and hardly ever are distributed. In this paper we propose a flexible strategy for execution of those legacy codes, identifying main modules involved in the process. Key technologies involved and a tentative implementation are provided allowing to understand challenges and limitations that surround this problem. Finally a case study is presented for a large-scale, single threaded, stochastic geostatistical simulation, in the context of mining and geological modeling applications. A successful execution, running time and speedup results are shown using a workstation cluster up to eleven nodes.