Subtitles for AVCHDs

I have some .sup files from an NTSC DVD and want to use them for a custom AVCHD I have made.  Are .sup files from a DVD compatible with AVCHD or do I have convert them?  (I plan to mux them in with tsmuxer and don't need to change the timing of the subtitles at all.)

EDIT:  Well tsmuxer won't accept them, so I suppose .sup files are not compatible.  How do I convert them?

Convert them to .srt with multiAVCHD

Thanks, Fremendar. :)

.sup, Chew?

...

Thanks, I'll be here all week.

TV's Frink said:

.sup, Chew?

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Thanks, I'll be here all week.

lol!  Nothing's .sup now.