Scripting help for my avatar

I'm building a Transformers avatar and as part of the transformation, i need one my arm attachments to move 0.3m in the Y-axis. I tried to use llSetPos but that only caused the attachment to slide about 8m away in the wrong direction.

My usual solution to this problem is to double up the prims and have them change between their usual texture and a transparent one, but this isn't an option since the attachment has 40-50 prims already.

Can anyone help me out with this?

I suggest having the scripts record the locations and rotations when you have manually put them in the right place. There are already some scripts out there that do it (e.g. Puppeteer), but it isn't hard to implement yourself either. I think it is more an issue with rotations than translations, but attachments can behave really screwy when you try to actually calculate positioning.

Don't forget the Transformer transform sound!

How do I do that?

Any command I've tried gives me the region coordinates, not the coordinates in relation to my avatar. I've tried llGetPos, llGetObjectDetails and llGetObjectParams.

I looked for Puppeteer, but the free version is no mod, no trans and I plan on selling this avatar.