Over the past years, the reengineering of legacy software systems to object oriented platforms has received significant attention. In this paper, we present a generic re-engineering source code transformation framework to support the incremental migration of such procedural legacy systems to object oriented platforms. First, a source code representation framework that uses a generic domain model for procedural languages allows for the representation of Abstract Syntax Trees as XML documents. Second, a set of transformations allow for the identification of object models in specific parts of the legacy source code. In this way, the migration process is applied incrementally on different parts of the system. A clustering technique is used to decompose a program into a set of smaller components that are suitable for the incremental migration process. Finally, the migration process gradually composes the object models obtained at every stage to generate an amalgamated object model for the whole system. . A case study for the migration of a medium size C system to C++ is discussed as a proof of concept.