Custom repeat of calendar event- allow for choosing every other month or other variation

I'm trying to customize and host a repeat event that happens every 3rd Wednesday, every two months ( bi-monthly even). It looks like I can only customize the frequency by only one option, either "every X days/weeks/months/quarters/years" or "on the X day of every month". 
Right now, I have to input each event separately. Could you please create the option so that I can choose it to elect to repeat every [insert #] months, on the xnth [insert day: Mon/Tues/Wed/Th/Fr/Sa/Su)] of the month?