Scheduling Query

Dear Gurus,

I am maintaining in house pron tiome and gr processing time and smk is zero only.I am getting the planned order at the reqmt date only.My scenario is backward scheduling.Say If i give the demand on 1/09/2008 I am getting planned order 1/09/2008.If i convert to production order leadtime scheduling is happening and dates are redermined as per routing timing.In my scenario while converting To production order.Production order finish date should be 01/09/2008 only.What settings i have to do in backend and in fronend to prevent lead time scheduling while converting to production order.

Please through some light in this regard