To successfully convert FrameMaker autonumbers, it is best to use FrameMaker paragraph numbering facilities consistently. For example, if you use <$chapnum> for some paragraph formats in a given autonumber series, use it for all formats in that same series.
§6.7.5.1 Understanding autonumbering options in Word
§6.7.5.2 Converting autonumbers to Word SEQ fields
§6.7.5.3 Converting autonumbers via Word style sheet