Modeling languages play an essential part in the software engineering process. Currently, mostly UML is used for that purpose, but domain-specific modeling languages (DSMLs) get more and more attention. Their main benefit is a higher abstraction-level, which eases generating code from such models. One major drawback of DSMLs, is their time-consuming development. To tackle this problem the EMF Profiles project was founded. It provides a lightweight extension mechanism, just as UML profiles, to be used for DSMLs. This way models can be altered without modifying their whole metamodel and domain properties can be reused, thus reducing the required development time. In comparison to pure metamodel-based languages there are certain limitations in EMF Profiles. There is no way to model constraints regarding the restricted use of stereotypes or to include runtime behavior. A typical use case is for example to use multiple languages at once. However, considering these shortcomings, such an attempt is not possible. Thus the question emerged, how these features can be realized. In this thesis two extensions to EMF Profiles are presented and implemented as prototype, which is then evaluated using a case study. The research problems were solved by introducing an OCL constraint mechanism, which manages the stereotype application. Furthermore a generator was implemented to add AspectJ-based code fragments to profiles, so they can influence the runtime behavior of a model element. The case study was conducted by creating a base Petri net language and adding three Petri net extensions, implemented as EMF profiles, to it. All of their specifications could be fully implemented. Further metrics about the approach and the prototype were collected, in order to ensure it is assessable and comparable.