you could bring the "import" sequence into the other one as a nest.
it's markers will be on the nested sequence.
you could do a copy paste PLUS bring in the nested sequence as a guide.
the nested sequence can be invisible (the correct FCP lingo is un-enabled, and it's Control B to do that) and the markers are still go-to-able
if you really want the markers you could use one of Andreas Keil's XML tools
[
www.spherico.de]
i would have suggested XML2text,
it does this: "Get Clip level Markers out of a Sequence and lift them to Sequence level markers"
but it doesn't mention going the other way, which what you need,
there's also this little problem:
"The current version is unfortunately not compatible with FCP 5 XMLs. There will be an update soon.
People how are interested in beta testing should contact me."
nick