nsKeyHook plug-in
Wrote this small plug-in so I could validate input of a product key in a client's installer. They've let me release it :). You can handle WM_CHAR for example to only allow alphanumeric input and WM_PASTE to only allow paste of alphanumeric text. You can also handle WM_PASTE to automatically fill all product key fields (e.g. 5 text boxes for a 25 character product key).
Allows handling of WM_CHAR, WM_KEYDOWN, WM_KEYUP and WM_PASTE through NSIS script. WM_CHAR in particular can be used to validate input bySee the example scripts and readme for more information.
suppressing or allowing certain keystrokes.
http://nsis.sourceforge.net/NsKeyHook_plug-in
Stu