rsync via ssh tunnel

[Radio Gong 2000 GmbH & Co. KG [Technik]]

Hi there,

I want to put these two commands in just one command:

ssh -i ~/.ssh/id_dsa -C -l sascha -L 873:rsync-server:873 bridge-server
rsync -auz rsync://user@localhost/share /local-path

How can I do this. With Option --rsh (-e) rsync wants to execute the command 
on the remote machine and not on localhost as I want it...

rsync -au --rsh="ssh -C -l sascha -i ~/.ssh/id_dsa -L 873:rsync-server:873 
bridge-server" user at localhost::share /tmp/

Or does anyone know how to wirte the 2 commands in a script and getting first 
the tunnel and after execute rsync on localhost???

Greetings 

Sascha