To define multiple Extended Parameters values, use a backslash before quote. Reference the example to see how to use this feature:
i:\sbsrvr\bin\srvrmgr.exe /g gateway /e entServer /s SIEBDEVSRVR /u sadmin /p passwd /c "START TASK FOR COMPONENT EIM WITH CONFIG=htcontacts_tpl2.ifb, ExtendedParams=\"BatchNum1=200001,BatchNum2=200002-200003\", CONNECT=SiebSrvr_CRMSIEBDEV, ERRORFLAGS=1, TRACEFLAGS=0, SQLFLAGS=0"