Have you installed the Asus drivers? I seem to recall there's an Asus utility that would allow you to change the scale, it may just be having the correct video driver.
Edit I don't see anything for the Toshiba, but you could try a virtual screen extender such as gimespace or you can try forcing "pan and scan" functionality by using an XP driver as mentioned here
Just to let you know, I've tried the above with an Asus EeePC 1001PX-BLK033S, AND IT WORKS.
This netbook has an Intel GMA 3150 graphics card and came preinstalled with Windows 7 Starter.
The intel GMA driver for Windows 7 version 18.104.22.1689 [23/09/2009] did not allow me to set up pan-and-scan. The "Hide modes that this monitor cannot display" checkbox was grayed out. I could set screen resolutions larger than the native 1024x600 (e.g. 1024x768) but these were scaled down to fit on the screen - no panning.
This is what I did to get it working:
-Download the Intel GMA 3150 driver for Windows XP (latest version is 22.214.171.12460 [25/04/2010] as of this writing) from the Intel driver support site.
-Uninstall the Intel GMA driver for Windows 7 via add-remove programs, then remove the video cards from the device manager as well.
-Unzip and install the Windows XP driver (activating Windows XP Service Pack 3 compatibility mode and administrator rights for Setup.exe).
-Windows will detect the video card and try to install a driver for it. The version 8.xx driver seems to be still in there somewhere (I think it comes with Windows 7), and since it's a newer version, Windows 7 will choose it over the version 6.xx, which is the one we want. So wait until it's done installing version 8.xx, then open the device manager and update the video card driver. When prompted, choose to find a driver manually, then to choose a driver from a list. You should see both versions 6.xx and 8.xx in there, choose the 6.xx and click Next. Finish the update. If you don't see both versions 6.xx and 8.xx, reboot and try again.
-Reboot. With any luck the video card should now be using the Windows XP driver (version 6.xx). Then, that "Hide modes that this monitor cannot display" checkbox should be enabled, allowing you to uncheck it.
- Follow step H from the above post by Daniel_L to enable pan-and-scan.
At this point I have two "Intel(R) Graphics Media Accelerator 3150" video cards showing up in the device manager. Both are using the XP driver (version 6.xx). I believe one of them drives the internal LCD and the other the external VGA but I'm not sure.
I'm posting this from a 1280x1024 pan-and-scan desktop :)