How to publish from non-SQL Server data sources???

Scenario:

The SQL is the central Database.
At the night the server will push Artikels to serveral (500) Access Databases via Internet.
Most of the POS needs different data.

At the day the Access Databases at the Point of sale will create serveral billing informations.
The server will need this billing informatinons so soon as possible.
Ouer customer will use a dial up connection between Access and Server.
Now the problem is how to pull this informations from Access or how can i publisch from the Access Datatabase to the Server.
Then if the information is on the SQL Server have to push it to a ORACLE 8 System..

Thanks
Uwe