Hey guys,

I'm new to Zbrush and I find myself in trouble with topology.
In fact, I've recently decided to start a personal project : creating a weapon in Zbrush
I've been doing the whole design of my model and I learned how to used Dynamesh wich unfortunately destroyed my subdivision levels. Now that my model is done i'm no longer able to switch my subdivisions level ...

So I had to retopologize parts of my model : I did it with TopoGun 2 wich seems to me easier and faster than Zbrush tools.

Because I used another software for this part of the production, I now have two separeted objects :
My low poly ( as one .obj file based on the original ) and my high poly ( the original .obj file ).

For instance with the magazine :
http://www.hapshack.com/images/ZsRt5.png
http://www.hapshack.com/images/PpR9b.png


I'm wondering how to apply my normal map of my high detailed object into my new low poly ...
I've seen a lot of people doing it by changing the level of subdivision of the same model to get bump map, normal map, ...
But in my case I don't really know what to do, is there a way to say to Zbrush that it's the same subtool ?

Can someone help me ?
Thank you !