You can do this using my Account and Ticket Generator
The Config file allows you to specify what characters will be used to generate both usernames and passwords
I have made my software available in a website at the following location:
http://www.softreg.co.uk/HSGAccountTicketGenerator/
You can download it from there.
It will print tickets to just about any printer which is set up to print on a windows machine but is specifically designed to print to 'strip' tickets so will waste paper if you are printing to A4 or Letter (or similar).
I use a very simple POS58 thermal printer which I bought on eBay and it works fine.
The software must be licensed to get all of the functionality working (I may be persuaded to give a few licenses away for free to people who are prepared to help with testing it for me, not everyone though!).
It also uses an MS-SQLServer database for accounting which can be disabled. In theory, it should also work for other databases but I have not tried it and would be interested to hear from people who set it up to run against MySQL etc.
I will write up some documentation when I have chance as there are a lot of features which will need a little explanation.
Have a look, tell me what you think and we will see how well it works!