Arduino and LPT Printer: help to control position directly by LPT

I am trying to control the position of the cartridge of a HP 670C connecting things as in: Arduino Forum
I can print text. But what I need is to control paper position (sometimes towards the printer and sometimes backwards by the same way) and cartridge position. Moreover, I need the cartridge stay in a position when I want, wait and then go to another position. The same for paper, only moves when I order that.
I want to do that without removing the case and without interfere directly the steppers, encoders, etc. Just by a direct connection as in the link above.
I downloaded some manuals of HP PCL (Printer Command Language) and tested lots of things, including relative and absolute positioning, negativ motion, among others. It was impossible for me to reverse the paper sense (which is actually very easy working directly with the steppers...and which the printer do every time the sheet entered in a bad way) and also I could not stop the cartridge in any position.
Can somebody tell me if this 2 things (paper position control, cartridge position control) can be done just using direct connection to the parallel port of the printer? Some advices?
Thanks in advance