log's offset and return updated analogs.
 
  BTKSETANALOGOFFSET(H, INDEX, NEWOFFSET) modifies analog's offset by NEWOFFSET for 
  the analog at the index INDEX. This offset is used to convert numeric data into analog 
  data or vice versa.

  The analog to modify can also be selected by its LABEL.
  BTKSETANALOGOFFSET(H, LABEL, NEWOFFSET)

  This function can also returns an updated list of analogs.
  ANALOGS = BTKSETANALOGOFFSET(H, INDEX, NEWOFFSET)
  ANALOGS = BTKSETANALOGOFFSET(H, LABEL, NEWOFFSET)
  The