The image formed by a telescope, depending on the position of the object, has range from the "least distance of distinct vision" (which is about 25 cm) to infinity. In other words, the closest distance from the eye-piece of the image in a telescope is 25 cm.
However, the object distance of a microscope is normally a few cm. Assume that the objective of the microscope is placed as close as possible to the eye-piece of the telscope, then the "object" seen by the microscope (which is the image of the telescope) is at least 25 cm away, that probably could not form a good final image.