The T45 has a parallel interface. If your computer (you didn't tell us what model you have, so just guessing here) has a parallel port (it will be a 25-pin connector, with the individual pins being female) then all you need is almost any parallel cable. What do you mean by "the old cable does not work"?
That OLD OfficeJet T45 is just a accident waiting to happen, a time sink hole.
It only has a parallel interface (also called a Centronics interface, or an IEEE-1284 interface) and if you wanted to try and get a parallel-to-USB interface cable that is only part of the problem you are going to run up against, assuming that it works adequately to begin with.
Even with the converter, you then have to try and find a proper driver for your operating system. That might not be real hard, since there are a lot of drivers made for old equipment that is for the WinXP OS. Seems like a lot of those old driver suppliers want some kind of money, though. And it it is an outside supplier of WinXP drivers, then there is always the possibility where they require you to install some "Driver Updates" program on your computer as well. Doing that you may easily install some spyware on your PC as well.
For not much more than the price of the parallel-to-USB converter you can probably find a complete new USB interfaced printer at one of the big-box stores, or maybe one of your local discount computer stores. Look around.
If your computer just has USB ports then they really are better. Even if you have both USB and parallel ports... use the USB whenever you can. That is, get USB devices for your USB ports. They are better, smaller, cheaper, faster, more "intelligent" (USB communicates better to the computer).