you may need to create an expression...to perform the math to return the value you are after...this may or may not require creating a user defined proprty for both Latitude, and Longitude such that the expression operators can operate on them
I'm just not sure what that math would be TBH.
OK, so the formaul a is:
Degrees Minutes Seconds to Degrees Minutes.m
Degrees = Degrees
Minutes.m = Minutes + (Seconds / 60)
So you could do this...
Create all your points...create a new point file format that includes Lat Long Deg, Minutes and Seconds...export your points using that format, then reimport them
Then a user defined property for each value, then do the math use the resultant in your label