how to import/export custom workflows between project areas

Are any best practices documented for editing the XML source code for RTC process configuration? Here's my use case:

I have created a custom workflow, which includes a few new states, actions, attributes, and editor presentations to a process configuration based on the Scrum process template. I would like to add this workflow to another project area. I implemented the workflow using the various visual, item-specific process configuration editors (Project Configuration > Configuration Data > Work Items > {Types and Attributes, Workflows, Editor Presentations, etc}.

I've done the above twice: once as I developed the workflow initially, then a second time to re-implement in a second project. I would now like to add the workflow to yet another project.

Is there a way to do this more quickly, with less chance of error, than by re-implementing yet another time, using the individual visual editors? I'm looking for something akin to exporting a process template, but instead of dealing with an entire, monolithic process configuration, I want to export and import just the changes related to my custom workflow.

I've looked at the XML source in various ways, but I don't see an obvious way to pull the workflow from the source project and add it to the target project. The custom workflow is implemented in multiple <configuration-data> elements, some of which also contain configuration data for items that are unrelated to my workflow.

Has anyone tried to do something similar? How? With what results?

Thanks,
Scott