No, there currently isn't an Open Office .sxw plugin that we're aware of.

However, in theory it would not be too difficult to write one, since
OpenOffice uses open standards; a .SXW file is really a zip file which
contains the following files:

content.xml (contains the marked up document content)
meta.xml (contains document meta-data)
settings.xml (various settings to do with screen and printer dimensions)
styles.xml (font face and line/paragraph settings)

Hope this helps

John McPherson