Is it possible, nobody has come up with a way to sum timecodes in Excel without either being a programmer or manually input the data in some alternative format? There is a macro going around but requires manual input, excluding frames, to work.
Excel math is base 10. Because 99.9999% of the people who use it use it for things like accounting and managing real numbered projects. Timecode math isn't "real" math, unfortunately. So it doesn't work with base 30 or base 24 or base 25, base 60...etc...which is what timecode is.