Limiting the length of a vector in VIVA

Hi

Is there a way to get an arbitrary length of samples using the "value" command?  I have it set up to gather from the starting point and using the ?period argument I have it resampling but I only need 128 (but probably want ~140) samples and it's giving me the rest of the waveform.  As I'm asking this I realize I can probably do a clip then the value command but are there other ways?

Thanks

Chris