You could use the Biomedical Startup Kit for what you are doing: http://zone.ni.com/devzone/cda/tut/p/id/6626. If not, you could simulate any sine signal as long as you have the amplitude, phase and frequency information by using the 'Sine Waveform' VI (Functions >> Programming >> Waveform >> Analog Waveform >> Generation >> Sine Waveform).
I hope this helps.
I am not sure I understood what you meant by a 'project'. If you download the Biomedical Startup Kit, you will be able to see all the functions that should help you get started on the ECG Simulation. I hope this helps.