Found a workaround...in the desktop calendar app you can do this, it just means waiting until you get home to make the event repeat on certain days of a certain week of the month. So for now, I can enter events in the phone as I find out about them when I am out of the house, and when I get home and sync the phone i can then make the event repeat as I want. It's a bit of a pain, but at least it will work.
UNLESS the event occurs on the FIFTH such day in a month. Calendar only supports custom events for FOUR weeks.