Ok...
First, the P directory actually contains primitives, not parts. Primitives are things like boxes, cones, spheres, etc. which save time when authoring parts. You wouldn't want to model a stud a thousand times, so there's a primitive for that, which is included via line type 1.
Second, line type 5 doesn't alter the model, and it doesn't have a-i values, those are only present in line type 1. They define a transformation matrix which scales, rotates, etc. the subpart (or primitive) being included. The only things line type 5 does is either draw a line like in line type 2, or do nothing, depending on the angle from which the model is being viewed.
Perhaps if you would tell me exactly what you are really trying to do, I could help you out. Why are you trying to have your part modify itself? (Is that what you're saying?) That doesn't really make any sense in the context of authoring parts. If you want to create something once and use it multiple times, that is achieved by creating a subpart and including it multiple times via type 1 lines.
I appreciate your initiative in trying to help author parts, I really do. But please, read and understand the official parts specification before trying to proceed, it will save you many headaches as it did for me. I would suggest starting by making a few simple test parts just to understand the way LDraw works before proceeding to make actual lego parts.
First, the P directory actually contains primitives, not parts. Primitives are things like boxes, cones, spheres, etc. which save time when authoring parts. You wouldn't want to model a stud a thousand times, so there's a primitive for that, which is included via line type 1.
Second, line type 5 doesn't alter the model, and it doesn't have a-i values, those are only present in line type 1. They define a transformation matrix which scales, rotates, etc. the subpart (or primitive) being included. The only things line type 5 does is either draw a line like in line type 2, or do nothing, depending on the angle from which the model is being viewed.
Perhaps if you would tell me exactly what you are really trying to do, I could help you out. Why are you trying to have your part modify itself? (Is that what you're saying?) That doesn't really make any sense in the context of authoring parts. If you want to create something once and use it multiple times, that is achieved by creating a subpart and including it multiple times via type 1 lines.
I appreciate your initiative in trying to help author parts, I really do. But please, read and understand the official parts specification before trying to proceed, it will save you many headaches as it did for me. I would suggest starting by making a few simple test parts just to understand the way LDraw works before proceeding to make actual lego parts.