[Valmont]

Originally your code created an instance of struct "object".
(Don't name your structs, classes, and types with only lower case letters next time).

object * start;
  start = new object;

And your struct set us up a matrix of ints.

struct object
{
  //For now, lets test on a 5x5 matrix
  object()
  {
     array = new C2DVector<int>(5,5);
  }

  C2DVector<int> *array;
};

That means: that is the intention, looking at the declaration of C2DVector<int>*.
But this code is faulty anyway (although compilers accept it!).
So I've adapted it:

class object 
{
public:
  object() : array(2,2) //  this has been changed now.
  { }  
  C2DMatrix<int> array;
};

So I haven't changed anything. If I did, then your struct is ambigious.

All in all, this stuct of int-matrices work perfectly:

class object 
{
public:
  object() : array(2,2)
  { }  
  C2DMatrix<int> array;
};


int main()
{  
  try
  {
    object start;
    
    start.array(0,0)=1;
    start.array(1,1)=2;
    cout<<start.array<<endl;
  }
  catch(C2DMatrixError& err)
  {
    cout<<err.what()<<endl;
  }
    
  return 0;
}