Can this be done? I can ssh to my home box on port 80, but can't figure out how to specify the port for pscp or psftp.

pscp? psftp? These are typically window's ports of SSH clients that come with PuTTy.
So you should probably google for PuTTy ... I only know about OpenSSH's scp and sftp.

SYNOPSIS
scp [-pqrvBC46] [-F ssh_config] [-S program] [-P port] [-c cipher]
[-i identity_file] [-o ssh_option] [[user@]host1:]file1 [...]
[[user@]host2:]file2

... so if you want to scp to a sshd server listening on port 80 you could do this ...

scp -P80 myfile goofy@dizzydorf.com:

sftp is a bit different ...

sftp -oPort=80 dizzydorf.com

Be aware that 80 is typically the port httpd (like apache) use. You can check to see what is listening on port 80 with telnet.

$ telnet dizzyland.com 80
Trying 10.10.10.40...
Connected to dizzyland.com.
Escape character is '^]'.
SSH-1.99-OpenSSH_3.5p1

That means sshd is listen on port 80 on your remote system.

Typically, windows uses a /? instead of --help or -h. For your convenience it is -P, below are the other options...

Z:\>pscp /?
PuTTY Secure Copy client
Release 0.53b
Usage: pscp [options] [user@]host:source target
pscp [options] source [source...] [user@]host:target
pscp [options] -ls user@host:filespec
Options:
-p preserve file attributes
-q quiet, don't show statistics
-r copy directories recursively
-v show verbose messages
-load sessname Load settings from saved session
-P port connect to specified port
-l user connect with specified username
-pw passw login with specified password
-1 -2 force use of particular SSH protocol version
-C enable compression
-i key private key file for authentication
-batch disable all interactive prompts
-unsafe allow server-side wildcards (DANGEROUS)