Charitable Mileage Entry

In the Deductions & Credits section when entering mileage and travel expenses there are only two options, once and multiple times.  Under the multiple times it presumes the miles driven are the same each time and multiplies it times the number of trips per year.  As an elder and trustee for my church I have a log with multiple trips (128) for multiple distances and multiple reasons for one organization (i.e., my church). How can I best enter that?