Since you are using E1, then the solution lies within E1.
- Create your database with appropriate security and permissions on UDB.
- Create a data source in E1 to point to your new database.
- Use R98403 running LOCAL on a fat client to copy all the tables and data from a data source on the AS/400 to the UDB database.
- Repeat the above for each data source you are moving over (Business Data, Control Tables, System, Data Dictionary, PD, PY, DV, etc.).
Yes, it will take a really long time, but I don't see any other way unless somebody knows of a data migration tool.