i have tried the -batch -e ExtractModelFromSequential in v5r8 and all it will do is say:
extractfromsequential report
sequential file to process <f:\xx\rsassy.exp>
output directory <f:\xxx\xx>
generate model <xxxx+-rs+-whl'cld+-assy+-315-79563:000-0+-30sep02'sent+-to+-ube+-9oct02.model>...