Are you talking about XPression Clips or the XPression Studio Sequencer? Do you want to know the total length of media clips, or the remaining duration of a playing XPression Take items (the "duration" column int he sequence view of Studio?
For the first one, you would have to use VDCP. For the second one, you can use the XP plugin. Let me know which you want, and I'll cook up a quick example.
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