creating a patch bundle with no physical access to target repository

I've been reading the manual up and down and maybe I'm missing
something very obvious...

I'm working on a project with a collegue and I don't have physical
access to his repository (nor does he to mine). Occassionally I would
like to send him a bundle of patches that he can 'darcs apply'. I know
exactly which patches I sent the last time. It feels like I want to do
something like 'darcs send --from-patch patch1 --to-patch patch2 -o
patchbundle' but the send command requires me to have access to the
target repository. Which I dont!

Thankful for any pointers.

Cheers,
Jon