[Typo3] capture FE username into form

[jason knight]

Greetings List,

I'm trying to create a form that would 'capture' the front end user's 
login name (I'm using the macmade plugin) so that no one else could 
submit the form saying they were someone else. The form is password 
protected.

I am planning on using the mailformplus plugin to capture the 
information to the DB and output it as a csv. Basically it is a mail 
forwarding service where we will capture the user's login name (their 
email address) and forwad their mail to the account they put in.

I've searched the usual sources with no success.

Thanks in advance.

-J