Option to raise 2008 R2 functional level without 2008 DC but just having 2012 DC

Hi,

Can i raise the functional level from 2000 to 2008 R2 without having 2008 R2 domain controller installed but instead having a windows 2012 DC.

I understand we can rollback windows 2012 DC functional to 2008 or 2008 R2. Does this mean that without having 2008 DC in environment i can rollback from 2012 functional level to 2008(R2) functional level ?

Here is my AD setup looks like
•Windows 2003 domain controllers in 2000 functional mode
•Exchange 2003 SP2.

Proposed plan is to raise the functional level from 2000 to 2003 and then introduce windows 2012 DC as additional Dc and raise the functional level to 2008 R2.

Would it be possible to raise the functional levels to 2008 R2 without 2008 R2 DC  ?

Thank you!