You will not be able to generate this signal with the 5670. The 5670 has a real-time bandwidth of 20 MHz and your 10 MHz noisy square wave has a bandwidth of 500 MHz. In general, to convert a real signal to an IQ signal you must perform SW downconversion from the center frequency of the real signal's spectrum to 0 Hz. These SW downconversion tools are available in National Instruments' Spectral Measurements Toolkit and Modulation Toolkit.
Thanks,
Andy