The notion of "level" is somewhat unclear here. It sounds like you mean you don't want the geometry in your "level" file, only where objects are located. A more clear term for what I'm talking about is "placement editor" (ie. use Blender to place objects around the scene)
I've written a script to do that using Python, it was pretty easy:
#!BPY
"""
by Joseph Hocking 5/1/2010
Name: 'Dropper'
Blender: 2.49
Group: 'Export'
Tooltip: 'Saves object info to text file'
"""
import Blender
import bpy
def write(filename):
out = file(filename,"w")
out.write("<ENTITIES>\n")
for obj in bpy.data.objects:
if obj.sel:
out.write("<ENTITY ")
out.write("PX=\"" + str(round(obj.LocX,4)) + "\" ")
out.write("PY=\"" + str(round(obj.LocY,4)) + "\" ")
out.write("PZ=\"" + str(round(obj.LocZ,4)) + "\" ")
out.write("RX=\"" + str(round(obj.RotX,4)) + "\" ")
out.write("RY=\"" + str(round(obj.RotY,4)) + "\" ")
out.write("RZ=\"" + str(round(obj.RotZ,4)) + "\">")
out.write(obj.name)
#optionally assign string property "tag" under "Logic" panel
try:
prop = obj.getProperty("tag")
if prop.getType() == "STRING":
out.write("<TAG>" + prop.getData() + "</TAG>")
except: pass
out.write("</ENTITY>\n")
out.write("</ENTITIES>")
out.close()
Blender.Window.FileSelector(write,"Export")
(I'm not sure this works in the latest version of Blender. You can see in the comments that I wrote this script a couple years ago, and I haven't upgraded Blender recently.)