If you have only to add a column to a VO you don't need to extend the AM.
To do this, you must create a new VO (e.g. XXReqSupplierVO) which extends the standard VO (e.g. ReqSupplierVO) substitute the standard VO with your new VO.
1. Right click on ur project file (xxx.jdr)
2. Edit Business Components Project...
3.Substitutions, Select the standard VO in the left panel and your VO in the right panel then click on Add Button
4. import the substitution on the server (running jpximport utility on your xxx.jpx file)
5. Bounce the OC4J(Apache) server
6. Ur new item on ReqSupplierLovRN page must refer to standard VO name (ReqSupplierVO), not to the personalized one. As you have imported the substitution on the server, at runtime when you refer to ReqSupplierVO the system, instead, use the extended GECMReqSupplierVO, so you can use your new column.
You don't have to create a new AM.My problem was different, because I needed to create a completely new VO, not to extend and existing one, so I had to add a new VO to the AM and that is why I would extend it.As it's not actually possibile I had to create a new page and to use directly my AM instead of the standard one. But this is not your case, I think.
In order to import them you have to right click on your project name and to choose "Import Business Components". Then you must select the server.xml file that you should find in the same directory (oracle.apps.icx.por.schema.server).