How to add E-Mail or Text-Form to CP auth page ?

[Nachtfalke]

Hi experts,

is it possible to add an "E-Mail textbox" on CP authentication page which allows the user to send a question to the support without beeing authenticated ? Or can this be done on the squidguard block page ?

my intention is that if someone has problems with CP or some sites were block that the user can enter its questions into a textform and this will be send to my admin email address.

Can this be done ?
Any example codes ?
Where are the username/password and destination email addresses stored? I don't want to show the credentials to everyone who is looking into the source code ;)

As you can see - I am not the expert for this ;-)
But I really appreciate your help!