Visual C++ :: OBJ Conversion - XML Structure

I'm trying to make OBJ converter. The file structure of which I am trying to convert is an XML structure. Here's an example. I currently have a lua script that does this for me. But it always crashes on big objects. It's for a game called "ROBLOX" The only information I need to convert is.

<int name="BrickColor">194</int> <-- Brick Color
<CoordinateFrame name="CFrame"> <-- Position
<X>0</X>
<Y>0.600000024</Y>
<Z>0</Z>

And

Vector3 name="size"> <-- Part size.
X>1000</X>
Y>1.20000005</Y>
Z>1000</Z>

Here's the lua script. [URL] .....

This currently grabs all of the ClassNames in the place and converts them to OBJ wavefront gemotry.