The scenario is:
1 - from PC I open ftp connection (port 21) to server1
2 - from server1 I open sftp connection (port 22) to server2
3- pass file from server2 to server1
4- pass file from sever1 to PC
It looks like using the tunneling feature I can pass the file from server2 to PC.
but the tunneling in in port 6000-6100 in in my scenarion the tunneling is via ssh / ftp ports that are not in this range
Please read documentation to learn how tunneling in WinSCP works. WinSCP does not support what you ask for.