Excel UDF to calculate distances using lat/lon

I had been using a UDF that was posted here (or linked here) to calculate distances between two points using Excel and changed it to do driving time instead.

I have many addresses and have noticed that a couple cannot be found by Mappoint, but I have determined their respective Lat/Lon.

However, I do not know what format one could send the Lat/Lon so that MapPoint can locate them.

My concern is that I would have to change all of the addresses to Lat/Lon -I rather not have to.


Thanks in advance