Visit
groups.google.com/advanced_group_search?q=group:*Excel*&num=100,
type in [test user key  press] without the [], and browse through the
results. That should get you started.

The best early result is
groups.google.com/.../browse
_thread/thread/810554bd81a31fb0/f3c0340853f05e7f?lnk=st&q=&rnum=5#f3c034
0853f05e7f - you should now search for &H11 and other key definitions.
Using Google web search for [&H11 VBA] I found this:
http://puremis.net/excel/code/061.shtml

For your code  portion, see the second web reference as well.