File interface from diffrent source to acess database

[Exadd]

We having this Human resource system that the company will be using however, the current payroll application will still be used as normal but the update will not be done on the same application.At the moment the current set up is that there a three database linked together that makes up the payroll application but for now one of this database will not be pupolated with data as it will now come from another source all together via extraction or file interface which is the new HR software.

The only problem I'm facing is some of those fields that i will need to transfer over to suit the current set up of the payroll application is not included on that new software file extract and i dont know where to start or what to do because abviously the file interface should consists of this mandatory field.Without seeing the relationship of what I'm talking about do you think its worth continuing this project as those wanted field are not included?And how can we go without these mandatory field?

[rpeare]

What are the mandatory fields. If you have some common field that identifies individual people (for instance social security number) you should be able to link it as long as the SSN is available in both systems.