Hi again,
Sorry for delay in getting back to you. If the forms are all built from the same XSN file, you can use merge forms. There are two ways to consider - manual (where the user indicates which forms to merge) and automatic (where some logic in the form goes out to a file share and imports all of the forms). Assuming that the file share is in the same domain (and not on your local computer), you can use a form deployed with default domain trust security for both. Merge forms requires a data source that supports aggregation.
Another method is to attach the other forms as file attachments. This is not as useful because the XML data is not as available to downstream line of business processes. I don't know if you have a downstream application that needs to process the forms or not, but you can either manually attach (use a repeating section with a file attachment in it), or programmatically loop through and attach the files (more work). You could even attach links to the files, but not sure that is useful. If the forms are not from the same XSN, you can still use the file attachment technique.
Personally, I recommend merging the forms, but that requires a data source that supports merging.
You can create logic that opens the other forms and submits them as part of your submit. That's much more work though, but if you don't have a data source that aggregates, or if file attachment isn't useful, that is one other option.
Good luck!
Patrick Halstead
Project Manager at Qdabra