I have a Minolta Hi Matic 9, made in 1956. Can the lens be removed in order to utilize a zoom lens.If so, which manufacturers would be possible choices?
The Minolta Hi Matic 9 has a fixed 45mm lens. It is not possible to switch lenses.
Lens variety and interchangeability – Nope, you won’t get that either. But, if you are the person that had to save up and finally got your Leica and lens, you probably can’t afford another lens for awhile anyway.
If I understand correctly (looking at the manual, pictures of the camera and repair advice for this camera), the shutter for this camera is in the lens and the lens isn't designed to be removed. Also, this is a rangefinder camera (so the user isn't looking through the lens to frame the picture).
Zoom lenses for 35mm normally are designed for SLRs -- where the shutter is in the camera body and the user looks through the lens to frame the picture.
So if you took a zoom lens from another camera and somehow managed to remove the existing lens and get the zoom lens attached to the Hi Matic you would not have a shutter. This means that, practically speaking, there would be no way to properly expose a picture or even advance a frame without light striking the film. Also, you wouldn't have a way to see what the lens was seeing.
A better solution would be to either enjoy the Hi Matic as it is, or purchase a used film SLR and zoom lens (designed to be used with the specific SLR you get).