Hi,
you may create putaway tasks automatically:
https://help.sap.com/saphelp_scm50/helpdata/en/08/802f418378ef23e10000000a155106/frameset.htm
then you may set up "Confirm immediatelly" in:
Cross-Process settings - Warehouse Task - Define Warehouse Process Type
check your settings for GR posting to ECC in:
Interfaces - ERP Integration - General Settings - Set Control Parameters for ERP Version Control
Petr