Buy another box
"xPrintServer enables wireless printing for iOS devices such as iPads® and iPhones® using their native print menu. It eliminates the need to print through apps, install software, or email yourself documents for printing. And more importantly, you don't need to buy a new printer because xPrintServer works with more than 4,000 top brand USB and network printers. "
You have to check whether this box supports your printer
To print from the iPad your going to have to install some more software:
-- many printer makers have iPad applications for their printers. Look in the app store
-- generic software like Printopia
iPad Print Applications -- usually free:
Lexmark and possible Dell
Helper app -- /print n share
Print directly to the widest range of network or WiFi printers available in any app. Alternatively print via your computer to ALL printers including USB & Bluetooth printers. View read and display large PDF, Office & iWork files. Easily transfer & store files from the Cloud or your computer.
more helper apps
You can connect the printer to a computer and install software on your computer to print from your ipad to the comptuer then to the printer.
Software for your computer's printer:
Mac and Windows
if the printer does not support airprint
you can use a computer with linux and cups installed (free)
cups now suports airprint
or you could use a raspberry pi, $25 US computer plus cups