Despite plink (putty link, which provides remote evaluation of commands on remote cluster by using ssh) is Windows application, I hope that You will help me in this question.

I have the remote connection to the cluster by using ssh. There are different nodes on the cluster. By default I get the connection to the node "b", at which my directory is located. When I want to make calculations, I need to use interactive regime for making them into strong node, called $s$:
      ssh s

Now I have the shell script on my local Windows machine which authomatizes procedure of calculations: I use pscp (putty scp) for sending file with initial data and plink for remote start of calculations on cluster (by launching bash script). However, I stuck with one problem. I can't make calculations on the node which I want. 

Precisely, I launch calculations through running the script (located on cluster) using following pscp command:
      plink -ssh -i mykey.ppk ~/script
By default the script (and hence the calculation) runs on "b" node. I want to make the calculation on "s" node. But unfortunately, I don't know how to force making of calculations on the node which I want. For example, if I simply write

      plink -ssh -i mykey.ppk -t -t ssh s ,

then the window with cluster under s node is opened, and script stops work.