possible to 'share' or 'link' to common directories?

Is there any way to share or link a svn-controlled directory so that it is 'commit-able' from two different roots?
 
E.g.,
 
\common
\a
\b
 
Directories \a and \b both have code that depends on code in \common. There are often changes made to both \a and \common and both \b and \common. I would like to have a link under \a and \b that is in actuality \common:
 
\common
\a\common(link)
\b\common(link)
 
It is possible to create Unix-like 'links' under Windows 2000/XP using the LINKD command. I've tried to do just that. The link shows up under source control, but a commit from an upper level directory doesn't find the sub-directory link.
 
Is there anything built in to SVN to allow something like this?
Received on Tue Jul 11 17:14:35 2006