[racket] Creation of lambda version with syntaxes.

Hi all,

I am currently working on creating my own language in racket. Therefore I would like to change the standard lambda implementation to a version in which a certain method call is interleaved between every 2 execution lines of the body. I am able to do this with the  constructs for creating macros and syntaxes but I don't see how I can extend the namespace in order to create a new namespace with the arguments of the lambda-call which will be used when calling the lambda function. I am fairly new to the syntax system, but I have experience in creating my own lambda implementations in a meta-circular interpreter of scheme.
Is it possible to give me any hints for extending the namespace in particular in combination with the syntax system?

Thanks in advance,

Simon De Schutter