Putting controls on an in office Laser Printer

Hi
I need some help with this. For the last three years we have been manually recording print jobs from our laser printer in the department for later billing to the client. Its an antiquated process that requires that every artist who does a print on the laser printer record it in a notebook.

We do not have the printer on the general network. Its hooked in directly by USB to one dedicated computer to maintain control over the print jobs. One guy receives the pdf file over the network, gets a job number and then prints the file to specifications (i.e letter or tabloid) records it in his book and at the end of the month the prints are tallied and each client is charged for it.

What I would LIKE to do is either install some kind of software that would enable me to put the printer on the network BUT have it regulate print jobs by only allowing the user to print the job if they have entered a job number.

OR keep the printer on one dedicated machine (as I have it now) but AUTOMATICALLY record each print job so that a Job number could be assigned after to each job. . .

I hope this makes sense. Its just that I need to justify the use of the colour printer by making sure we recover expenditure from each print. Ink IS expensive you know! lol

thanks