Advances in device miniaturization and wireless technologies are stimulating mobile ad-hoc NETworks (MANET) where mobile nodes can autonomously organize in a peer-to-peer mode, without requiring a statically deployed network infrastructure. Because of node mobility, the set of service components that MANET clients have at one-hop distance changes often during service provisioning. That continuous change in locally accessible services significantly increases the complexity of designing and implementing effective MANET applications. The paper claims the need of dynamic middleware supports for MANET, not only to address routing/configuration issues, but also to automate the re-qualification of service bindings at provision time. It presents COMMAND, a flexible middleware solution, based on code mobility, for transparent service rebinding in MANET. COMMAND exploits dynamically elected proxies that act as intermediaries to decouple mobile clients and needed service components. In particular, the paper focuses on how COMMAND implements a lightweight MANET-specific solution for effective code distribution to deploy the needed proxy behavior only when and where required. Finally, the paper shows the implementation of a COMMAND-based forum distributed application, together with its related performance, to point out how the proposed middleware can help service development in MANET.