if we define a pointer which points to some memory portion in mpb (e.g pointer with the type of t_vcharp which is allocated space by RCCE_malloc), the pointer itself will be stored in MPB (like the pointee) or in private memory of the calling core?
It resides on the private memory of the core. If you check the RCCE_malloc function, it uses a simple allocation scheme (GORY mode). The pointer you are reffering to is a part of a struct called RCCE_BLOCK. This struct is allocated via malloc and thus resides in the private mem of the core.