how can I map kinect color image to depth image?

Hi

I use labview to get color image and depth image from kinect. my goal is to detect a marker from color image and find it's depth from depth image. I was able to find the marker position in color image, but I have problems find it's depth. cause depth sensor and color camera are looking at different views. so my problem is to map the marker position from found on color image to the depth image. my inputs are 2D array of depth data, and the x ,y of marker on color image. the output that I need is z of the marker from depth data