Hi all,
I had exactly the same issue on Win2k8R2 and SQL-Server2012:
[Microsoft][SQL Server Native Client 11.0][SQL Server]Cannot find the object "DDLOG" because it does not exist or you do not have permissions.
To fix this,
you dont need to create DDLOG table manually and/or modify the SAPSPROT.TSK file !
Just download the latest Kernel 720 (or 721 should also work) and copy it to
\usr\sap\<SID>\SYS\exe\uc\NTAMD64
retry sapinst and after 10 Mins enjoy below nice message 
Execution of
SAP NetWeaver 7.3 > MS SQL Server > SAP Systems > Application Server ABAP > Standard System > Standard System
has completed.
Br,
Şahin Güney