Extract timeSheet inormation from RTC workitems using RPE

Hi all,
I'm tryng to export timeSheet information via Team Concerts REST Reporting API along with Rational Publishing Engine.

I use as source:
http://localhost:9443/ccm/rpt/repository/workitem
expecially the subcontainer
workitem.timeSheetEntry

I found out 2 problems:
1) only few attributes are presented by REST interface
2) it looks like there's no way to associate the timSheetEntry to the workitem

In this moment I'm only able to get report like: all the timeSpent by a single user or a Project Area (no details on single workitem)

Does anybody knows if:
1) timeSheetEntry details are available somewhere else (in REST interface) or it's planned to be included in a future API release?
2) Is there a way to determine which work item a individual timeSheetEntry is referring to (from RPE)?

Thanks and Regards
Luca