i never did it myself, but there are similar topics on the board like placing the name tag above a player and such.
Either use an ortho quad like you did, but then you need to convert the enemy (3d) coordinates to screen coordinates (2d).
Or use a Billboard Quad which is rendered in 3d and always aligned to the viewer.
i'd use the 2nd option as there is a sample Class someone posted which you can use see the links in ths thread 
Right. So im trying to use the textlabel example. I believe the code needs a bit of changing for jme2.0 and have done quite a bit of it myself. However im still stuck with one part - the bit of converting the FloatBuffer to texCoords on this method:
public Quad getQuad(float height){
Vector2f scales = new Vector2f();
BufferedImage img = getImage(scales);
float w = img.getWidth() * scales.x;
float h = img.getHeight() * scales.y;
float factor = height / h;
Quad ret = new Quad("textLabel2d", w * factor , h * factor);
TextureState ts = DisplaySystem.getDisplaySystem().getRenderer().createTextureState();
Texture tex = TextureManager.loadTexture(img, Texture.MinificationFilter.Trilinear, Texture.MagnificationFilter.Bilinear, true);
FloatBuffer texCo = ret.getTextureBuffer(0, 0);
FloatBuffer newTC = BufferUtils.createFloatBuffer(texCo.limit());
texCo.rewind();
for(int i=0; i<texCo.limit(); i+=2){
float u = texCo.get();
float v = texCo.get();
newTC.put(u*scales.x);
newTC.put(v*scales.y);
}
ret.setTextureBuffer(0, newTC);
ret.updateGeometricState(0, true);
// tex.setScale(new Vector3f(scales.x, scales.y, 1));
ts.setTexture(tex);
ts.setEnabled(true);
ret.setRenderState(ts);
ret.setRenderQueueMode(Renderer.QUEUE_TRANSPARENT);
BlendState bs = DisplaySystem.getDisplaySystem().getRenderer().createBlendState();
// activate blending
bs.setBlendEnabled(true);
// set the source function
bs.setSourceFunctionAlpha(BlendState.SourceFunction.SourceAlpha);
// set the destination function
bs.setDestinationFunctionAlpha(BlendState.DestinationFunction.OneMinusSourceAlpha);
bs.setTestEnabled(false);
bs.setEnabled(true);
ret.setRenderState(bs);
ret.setLightCombineMode(Spatial.LightCombineMode.Off);
ret.updateRenderState();
return ret;
}
In particular :
FloatBuffer texCo = ret.getTextureBuffer(0, 0);
FloatBuffer newTC = BufferUtils.createFloatBuffer(texCo.limit());
texCo.rewind();
for(int i=0; i<texCo.limit(); i+=2){
float u = texCo.get();
float v = texCo.get();
newTC.put(u*scales.x);
newTC.put(v*scales.y);
}
ret.setTextureBuffer(0, newTC);
ret.updateGeometricState(0, true);
I have studied the example from the hud tutorial which was changed and updated however I cannot work out what this example should be converted into to make it function correctly.
Please help,
Andy
JME Games threads seem to be grabbing more attention than support threads 
bumpedy bump
just comment the TextureCoords stuff out for now
i don't think its needed at all is it ?
got it showing at least, but if its not needed at all, why is it there at all? }:-@