Synchronizing Data Prior To Initial Snapshot

Hello folks,

I am trying to set up replication between a central office and multiple sites. This will be merge repl, since either central or satellites can be modified. However, one issue I ran into is setting up subscribers. I don't always have the option of starting with a publisher's snapshot; some of the subscribers have their own data already, which may or may not overlap with central site, and which needs to be synchronized into the central site somehow.

So far, I haven't seen any solution for this kind of scenario, at least nothing out of the box. Am I doomed to having to roll out custom data transfers (I don't think I can use DTS since all sites are running Express), or is there some standard way of doing this?

Thanks so much!

Sonya