How does the Migration from DCW AS400 to AX2009 looks like?

Hi there! :)

We're going to migrate a DCW AS400 System to Dynamics AX 2009,

but the main Problem is that we don't know, if there are any Interfaces on the side of the old DCW AS400 System, which we can use to start the data migration :/

Is anybody out there, who has done something like this before?

I'm looking for some Links and Tips :)

Thanks a lot!

Selo Yilo