In order to link a database file to a DSN, follow these steps:
Upload the mdb file using the file manager interface (provided by Ensim).
While adding the DSN, type the path where you have uploaded the mdb file.
For example, if you uploaded test.mdb file in ..\inetpub\wwwroot\databases folder, you need to specify: ..\inetpub\wwwroot\databases\test.mdb.
WEBppliance prepends the actual path on its own, therefore the Site Administrator will not need to.