Ok so you declare a 3d array first and specifying the size in subscript operator so to stor a pointers you wold do it like this
MyDataType* mydata3dArray[sizeX][sizeY][sizeZ];
//and use it this way
mydata3dArray[indexX][imdexY][indeZ] = Data;
Note that the size must be known at compile time and must be a constant value