Please clarify your question. The ORA_FFI package is used for making C calls on the server. If you wanted to do something similar on the client you could use WebUtil or create your own bean. Regarding Excel specifically, Oracle recommends using JACOB because it includes both the Java and C libraries needed to make calls from Forms to Excel on the client tier. If you wanted to use ORA_FFI on the server to call Excel, you would need to refer to the Microsoft documentation to determine what C functions they expose.