The control point objects are nested in a main object. Does each text file contain only one main object, or does it contain an arbitrary number of main objects (each of which contain an arbitrary number of control point objects)?
You can use a vector to store the control point objects as you parse through your file, something like this:
controlPoint temp; //used to store the data you parse for
//... (parse file for a control point object and store the data in temp)
temp.pointID = /**/ ;
temp.coordX = /**/ ;
temp.coordY = /**/ ;
controlPoints.push_back(temp); //store the data in your controlPoints vector
//... (at this point, temp can be reused for the next control point object you parse,
// and then it can be pushed back in controlPoints vector, until all the control points are stored in your vector. )
If your file contains more than a single main object, you'll have to keep track of the nesting level and the current object you are in (by parsing "Object =" and "End_Object" notations, and counting their occurance using a suitable variable structure), and perhaps maintain a similar vector for the file's main objects, each entry of which will contain the controlPoints vector you fill as you parse the main object.
If you are working with a very large number of points, and you want to use the data in your program for calculations that are memory intensive (and not just extract and save it in a new file, or something similar), you may want to implement the above with dynamically allocated arrays, because vectors have some memory overhead due to the fact that they allocate some additional memory as they grow, in order to store potential new entries to the vector without having to allocate new memory for each such new entry as it occurs (i.e. , the vector::capacity can be equal to or greater than the vector::size for a given vector).