mount cifs via proxy

I am trying to mount a windows shared folder via a proxy as the machine in question is behind a firewall. I can mount the resource just fine from within the network using

sudo mount -t cifs // /folder -o username=user,domain=DOMA.IN

I did not find any questions that mention mounting via proxy, there is this post in ubuntuforums which asks more or less the same question but has no real answer.

I tried to adapt what is used in that question and tried to open a tunnel

ssh -l user -C -L 1139:SERVER.DOMA.IN:139 PROXY.DOMA.IN

and then point mount to localhost 1139

sudo mount -t cifs //localhost/folder/ /folder --verbose -p 1139 -o username=user,domain=DOMA.IN

but this simply fails with a

mount error(6): No such device or address

Is this type of operation possible in principle and I am just doing something wrong, or is there an intrinsic limitation that makes this impossible?

Know someone who can answer? Share a link to this question via email, Twitter, or Facebook.