You might have to create two recurring events, one that recurs every 2 weeks on Wednesday, and another that occurs once a month, for the week in between.

Use "custom" for the repeat frequency to select the day of the week, and to make it every two weeks instead of every week.

Once you put the details in for one of the recurring events, you can copy it and modify the frequency.

This points toward a way to solving the problem. I need to set up two events, each on a monthly schedule, (1) for the first Wednesday (2) for each Wednesday except the first. It's easy to set up (1), but I can't find a way to set up (2), since I can't find a way to create an event that occurs every Wednesday of a month except the first one.