I will not repeat the great response that Carlos has given, but I just want to point out, that when creating a iDPR file you are basically creating a print/plot output.
So think of all the things that need to go into creating a plot and then you use this knowledge in creating the iDPR file. So if you wish to generate a specific look, try it first in Microstation, to see what it looks like and then set up the Automated iDPR the same way ( workspaces, user configurations, pen tables, seed files, levels, database connections, etc.). You can also issue specific 'keyins' as you would in the Microstation keyin window.
Though the process for creating a iDPR file is slightly different, what is going on in the background is opening a file from a seed file, attaching references, setiing a area, turning levels on/off, optionally defining a pen table, making a database connection and then creating a plot ( output is iDPR file).