The 2203 has an arbitrary waveform generator. You can specify the waveform as a CSV file, you can draw the waveform using the waveform editor or you can use and edit a previously captured waveform.
The output voltage can change up to once every 50 ns.
Your arbitrary waveform can consist of up to 4096 samples. These will be repeated indefinitely. The maximum rate that these samples can be streamed is once every 50 ns.
When you specify your waveform, you do so using values from -1 to +1. This range can be mapped from voltages ranging from +/- 125mV to +/- 2V. You can also apply an offset of up to +/- 1V
It might help you to download PicoScope 6 and have a play. www.picotech.com/software
Have a look at the 2000 series User's Guide and the PicoScope 6 User's Guide http://www.picotech.com/document
Hope this helps