Oddly enough, I would suggest your first drip-feed program should be one that fits in memory. The reason I suggest that is so that you can load a part program in the usual manner, then check that it can be executed. Once you know you have a good part program, then try executing it through drip-feed.
When drip-feeding to a Delta 20 control, all the same rules on loading programs apply including needing block numbers. The only exception is that, when drip-feeding, there is no need for the program title in parentheses on the first line (but the control knows to ignore it anyway if it is present).