|Do you mean create a Windows user or a User within the batchfile?|
Creating inside Batchfile
To prompt user input use;
Echo Enter First name
Set /p "firstname=>"
Echo Enter Last name
Set /p "lastname=>"
Echo Enter Username
Set /p "username=>"
If you want to use the username as a login you would need a login menu with an IF. And the same for password too.
IF %username% == mand0828 Goto :mand0828
IF %username% == Loq Goto :Loq
Echo Username doesn't exist.
Then you would have your Password set up at your block of code like.
Echo Enter Password
SET /p "password=>"
IF %password% == 123456 Goto :USERmand0828
Echo Password wrong!
Under :USERmand0828 you would put whatever else you want. That's the basic idea of username / password. Although I have to say that this way is very unsecure without a lot of coding to protect it. So it would be unwise to do it this way.
That's if you want it inside a batch file anyway.
If you're still new to it all, it would be best to mess around with the SET command for variables and the IF statements.
I hope this helps a little.