Yes when you set it in calender it should come up under "recurrence" you can set it as that calender day each month, or relative date aka last Friday of the month.
the problem is that it measures from the beginning of the month, so it would be the 4th friday of every month, not the "last" friday. if a months first day is on a friday, then you could potentialy have 5 fridays, and it would be early.
the only way i could think to do it other than that is to type them in manually. (there's is only 12 in a year, so do it for 2 years and you should be set till you get a new bb )