[CMake] how to get cmake and custom qt widget to work?

[eial at cs.bgu.ac.il]

hello.
I have a cmake+qt4 project, I needed to extend a certain gui item to suit my needs, I've been able to insert it into qtcreator and incorporate it into the project's gui, now when I run compilation, I get this:
/home/dagg/workspace/OSSM/src/GUI/ui_TrainingActivityManager.h:29:28: error: qstringspinbox.h: No such file or directory

the relevant part of /home/dagg/workspace/OSSM/src/GUI/ui_TrainingActivityManager.h is this:
/********************************************************************************
** Form generated from reading UI file 'TrainingActivityManager.ui'
**
** Created: Tue Oct 5 20:29:00 2010
**      by: Qt User Interface Compiler version 4.6.3
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_TRAININGACTIVITYMANAGER_H
#define UI_TRAININGACTIVITYMANAGER_H

#include <QtCore/QLocale>
#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QDialog>
#include <QtGui/QDialogButtonBox>
#include <QtGui/QFormLayout>
#include <QtGui/QGridLayout>
#include <QtGui/QHeaderView>
#include <QtGui/QLabel>
#include <QtGui/QLineEdit>
#include <QtGui/QPushButton>
#include <QtGui/QTreeWidget>
#include <QtGui/QVBoxLayout>
#include <QtGui/QWidget>
#include <qstringspinbox.h>  // line 28

QT_BEGIN_NAMESPACE

class Ui_TrainingActivityManager
{
public:
    QTreeWidget *mTrainActManList;
    QWidget *layoutWidget;

how can I make cmake work with this plugin, I've putted the hpp and cpp of the plugin within one of my sub project's src folder, also the file is called qstringspinbox.hpp.

any help would be appreciated.