While scanning the Click N Type on-screen keyboard is my default choice for whenever I have to use one, certain programs are noncompliant and have buttons etc. that can’t be accessed by keyboard — not even by the tedious Tab-and-Enter method. This total inaccessibility is not so frequent in mainstream programs, but it does happen. Therefore, switch scanners need a way to move the mouse sometimes. You can’t do this with the Click N Type, because it immobilizes the mouse cursor in scanning mode. However, you can use the Windows on-screen keyboard with the free Mouse Grid to move the mouse cursor — the cheapest option I know of. (There are, of course, commercial programs like Cross Scanner.)
The first step is to configure the keyboard for scanning. (You can use the Click N Type to do this, but bear in mind that you’ll need to be able to close it afterward. You can also use voice or physical keyboard.) The onscreen keyboard has slightly different menus in different operating systems, so all I can tell you is to look around to find the settings. If you have XP or Vista and you don’t have a switch input device, you’ll need to be able to press the physical Space key (the largest choice). If you’re feeling particularly patient and have AutoHotkey, you can also program other keys to act as the Space key. For example, q::Space. If you have XP or Vista and you do have a switch input device, you might need AutoHotkey to program your switch to act as a Space key rather than a mouse click. I do know that the Windows 7 keyboard, among its many improvements, gives the option to use a mouse click. However, this option WILL NOT WORK, because with that option the pointer has to be over the keyboard at all times. Therefore, you will need to program your switch or mouse click into a Space key anyway. For example, LButton::Space.
Once you have that figured out, you need to download Mouse Grid. See this post for how it works, as well as tips. Once you have Mouse Grid running, all you need to do is scan over the corresponding number and punctuation keys to jump the mouse cursor to the desired point on your screen. I know that there’s some assembly required, but it works when you need it.