Aldara Application

Does anybody know how to properly code for Aldara application (for viral warts in the vagina)? This can be applied by the patient when the warts are external. In Gynecology we have patients who need this within the vagina requiring the physician's skills.
I have previously advised them to consider this part of the basic E/M but they are wondering what other folks are doing.
CPT® 57150 Irrigation of vagina and/or application of medicament for treatment of bacterial, parasitic, or fungoid disease is not appropriate for viral warts.
Any help would be appreciated greatly.