Here is what I found during my testing today. This may be helpful to others who are trying to accomplish the same task. We wanted to allow our application which uses DOA to access both a 9i and 9i Lite datasource. 9i Lite would be used when 9i was not available.
DOA works with the OCA only when using the Net8 client (8.0.5 or 6). This works because Net8 had logic built into it that let's it interact with ODBC datasources by converting the OCI calls into ODBC calls via the OCA.
You can install Oracle Lite 8 (version 4.0.1) to get an Oracle Lite database, Net8 (the special version required to interact with the OCA) and the OCA. This configuration should work fine but you will be limited to using Net8 instead of Net9.
I tried to get Net9 to recognize the OCA but it dod not work. So, if we want to use DOA and the OCA we need to stick with Net8. Net8 should be compatible with 9i databases but it is not supported by Oracle any longer unless you have an extended support agreement. The OCA is not supported by Oracle any longer and has not been updated since Oracle 8.0.6.