This should be easy to figure out thanks to the clear text of telnet :D It shouldn't matter what platform your target is running. All you have to remember is that special keys like ctrl-z or page down, are just chars in the data stream. Ctrl-z is typically 0x1a, and I am not sure what page down is off the top of my head, but here is how you can figure it out:
- Get wireshark http://www.wireshark.org/ and install it if you don't already have it.
- Start wireshark up and capture all traffic on your NIC that will carry the connection to the target.
- Start a normal telnet session to the target and issue all of the commands (including the page downs and the ctrl-z).
- Stop wireshark capture and then filter out everything except telnet communication between you and the target.
- Look at the data that was sent to issue the ctrl-z, and page downs.
- Put those chars in your telnet stream when you are ready to issue those commands.
Easy.