nnimap-split-fancy across inbox boundaries?

[Pawel Osiczko]

Hello,

Having 2 IMAP inboxes defined, like so:

(setq gnus-select-method '(nnnil))
(setq gnus-secondary-select-methods
      '(
        (nnimap "0.foo"
                (nnimap-address "imap.foo.com")
                )
        (nnimap "1.bar"
                (nnimap-address "imap.bar.com")
                )
        )
      )

I would love to apply the split rules across the inboxes, ie if an email from 
user@example.com arrives at 1.bar, I'd like to move it to 0.foo:some-group:

(setq nnimap-split-fancy
      '(|
        (: nnmail-split-fancy-with-parent)
        (from "user@example.com"
             "nnimap+0.foo:some-group" )
        ("INBOX")
        )
      )
(setq nnimap-split-methods 'nnimap-split-fancy)

The above splits to the group named nnimap+0.foo:some-group at 1.bar. Any hints 
how to make the split happen across the inbox boundaries to 0.foo:some-group?

Thank you,

Pawel