Mirroring a git subdirectory in a SVN subdirectory -

yes, know there ton of version control questions on here, none of proposed solutions want them , can't find way hack 1 together. i've been looking week now.

my setup:

windows 7 machine (with cygwin-- though haven't touched problem), remote password-protected git repo , svn repo. gradually switching using svn git new projects (no 1 has used git before) , need shuffle code , forth.

what want:

i , several other people should able work in gitproject/path/to/sharedcode , have our commits automatically update svnproject/trunk/path/to/sharedcode. should affect 2 subdirectories, rest of repos should remain independent. i'm looking one-way, permanent link git subversion. history needs preserved in git, not in svn, no development take place there. additionally, repeatable in future can set anothersvnproject/trunk/path/to/sharedcode mirror in same way.

possible solutions:

• a script checks changes in gitproject/path/to/sharedcode (runs git diff) and, if finds any, copies them , pushes them svn repo. run automatically every day or called dev made changes.
• a script ^this^ run when making commits instead of running git push gitproject master pushes changes both git , svn.

or, if else fails,

• a clear, obvious workflow of can follow when working in git. "first, checkout gitproject command. create new branch named name command. make changes. go location , run command..."

what i've tried:

• subgit looks overkill our purposes, , don't want to/don't have authority set since it's not open-source. without creating new repo, well.

• using git-svn create new repo in gitproject/path/to/sharedcode git svn init --trunk=http://svnhost.com/svnproject/trunk/path/to/sharedcode --no-minimize-url. creates new local repo can push from, may useful batch script, it's not ideal solution.

• git2svn looks promising, can't find documentation it, don't trust it.

• i've used svn2git (the 1 written in ruby) before , worked beautifully, don't think has functionality need now.

• git-subversion bridge looks similar want automatic synchronization, again, it's complicated , involves setting whole new repo. if rest of team we'll end using this.

• i tried writing windows batch script described. went like: git pull latest version of gitproject, run git diff on gitproject/sharedcode , svnproject/sharedcode, pipe output txt file, use awful, awful windows if statement if diff picked besides readme, robocopy /mir contents of gitproject/sharedcode svnproject/sharedcode, robocopy correct readme backup svnproject/sharedcode, svn add everything, svn checkout remote repo, , svn commit. didn't work.

i'm sure have pieces of solution, lack knowledge , coding skills bring them together. i'm hoping stackoverflow can help.

1. you can't operate on part of tree inside git repo (in short words - it's monolithic object, contrary svn)
2. due p.1, must split git repository , convert /path/to/sharedcode additional special repository. can use submodules or subtree approach (trendy git-boys prefer today subtree)
3. with dedicated repo you, using git-svn, can add new remote svnproject/trunk/path/to/sharedcode (git-history mirrored svn, it's laziest , easiest way)