Changing the company code while upgrading to 12i

Hi,

We are currently in the process of mirgating to 12i. We want to resolve the issues while doing this process. We are migrating to 12i as it is and not doing any reimplementation.

1. We have more than 10 operating and out of which the Company code segment for two operating units are same. We would like to break this and separate company code by these operating units. Suggest a way to resolve this without doing reimplementation.

2. For we are maintaining alpha characters for Company code segment values. We would like to change this into numeric field option.

Please suggest a way to solve this issue.