problem with ogr ovf connection

[Janeks Kamerovskis]

I had succesfuly set up ogr ovf connection, but problem appears when I added
following field:

case when round(sysdate - RS.CREATE_DATE) < 14 then 1 else (
	case when round(sysdate - RS.CREATE_DATE) < 28 then 2 else 3 end
) end as RSS_AGE_GR

Problem is not in query because it runs without any problems directly in
F.ex. MS Query analyzer.

When checking with ogrinfo I am getting following output:

ERROR 1: Line 14: Didn't find expected '=' for value of attribute 'then'.
FAILURE:

What could be done to solve this problem?
One I probably know - to create a view on SQL server. Are there others?

Thanks in advance!
Janeks