Hello,
Note that CMD_API_FTP is the exact same thing as CMD_FTP... the only difference is what DA outputs.
So to do anything that CMD_FTP can already do (eg: suspend an account), you'd simply need to call the same thing, but with CMD_API_FTP instead.
Looking at the code, it might be a bit confusing, but it would be:
CMD_API_FTP
Method: POST
domain=domain.com
action=delete
suspend=anytext
select0=user
To unsuspend, same thing:
CMD_API_FTP
Method: POST
domain=domain.com
action=delete
unsuspend=anytext
select0=user
The only reason for action=delete is because it was added to the same form used to delete accounts, and was left that way to be backwards compatible.
John