Cast object pointer to char array

unsigned char *check = NULL;
 check = (dynamic_cast<unsigned char *>( ns3::NetDevice::GetChannel() ));
 

This is what i am trying. but the error is:

"error: cannot dynamic_cast 'ns3::NetDevice::GetChannel() const()' (of type 'class ns3::Ptr') to type 'unsigned char*' (target is not pointer or reference to class)"

I also tried:
reinterpret_cast

Buti does'nt work at all. Stuck with it. Please HELP HELP HELP...

---