Drew Roberts:
Button to play whole file.
Button to play first X (configurable) seconds of file.
Button to play X (configurable) seconds of file starting at position Y
(configurable).

Perhaps buttons 2 & 3 could be one button. Have two data entry widgets to the
left of the button, first holds X and second holds Y. Fill out from config
and allow override.

Ok.. see attached mockup. Its pretty basic, doesn't allow access to any "gritty details"..
but it should be a doddle to program. Let me know what you think.

Cheers, -Harry