How do I have the viewfinder image show in the LCD display

The XT does not have 'live view' - you can only use the LCD to view taken images

i think you are able too see the video in play back mode. so there is no problem in your LCD.
i think the CCD has got damaged in your CAM. that is why you are not able to view anything in shooting mode.
because CCD is the layer which converts the light falling on it to a electrical signal and shows us as a complete image.

Click the "disp" button. The display of the camera has been turned off in the LCD screen but you can still use the viewfinder, this functionality is just for those who prefer to use the viewfinder instead of the LCD screen.

You get to the viewfinder by putting an eye to it. The Rebel XT works as SLRs have worked for half a century, showing you the image through the viewfinder. Only more recent dSLRs have a Live View capability, allowing you to use them as point&shoot cameras by viewing the image on an LCD.

That is normal. Didital SLRs are different in this respect from digital compacts .

the ony way is to get the CCD replaced with a new one. Contact NIKON for free replacement as this comes under manufacturing defect.

If the LCD display is open, the viewfinder becomes inactive. Shut the LCD display, and the image should appear through the viewfinder. If there is still no image, the camcorder may require service.

If you turn on the back LCD, the electronic viewfinder will remain on while in a shooting mode. There is no setting on the camera to use only the back LCD monitor while shooting. If you playback images in the Play mode, only the LCD monitor will turn on. However, if you press the Monitor button while in the Play mode, than the back LCD monitor will turn off. The image will display only in the viewfinder LCD.

If you turn on the back LCD, the electronic viewfinder will remain on while in a shooting mode. There is no setting on the camera to use only the back LCD monitor while shooting. If you playback images in the Play mode, only the LCD monitor will turn on. However, if you press the Monitor button while in the Play mode, than the back LCD monitor will turn off. The image will display only in the viewfinder LCD.

If you turn on the back LCD, the electronic viewfinder will remain on while in a shooting mode. There is no setting on the camera to use only the back LCD monitor while shooting. If you playback images in the Play mode, only the LCD monitor will turn on. However, if you press the Monitor button while in the Play mode, than the back LCD monitor will turn off. The image will display only in the viewfinder LCD.