GetKeyNameText

int GetKeyNameText(DWORD lParam, LPSTR lpstr, 
    WORD wSize)

Retrieves a string that represents the name of a key.

Returns the length of the string, in characters, not counting the terminating null character.

lParam

Second parameter of the keyboard message (such as WM_KEYDOWN) to be processed. The function interprets the following portions of lParam:

Bits	Meaning
16-23	Scan code.
24	Extended-key flag. Distinguishes some keys on an enhanced keyboard.
25	"Don't care" bit. Indicates the function should not distinguish between left and right CTRL and SHIFT keys, for example.

lpstr

Address of a buffer that receives the key name.

wSize

Maximum length, in characters, of the key name, not including the terminating null character (this parameter should be one less than the size of the buffer pointed to by the lpstr parameter).

The export ordinal for this function is 133.