Here is the native function that seems to be the one you want (I am not entirely sure).
Public Declare Function RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" ( _
ByVal hKey As Long, _ ' Handle to open registry key
ByVal lpValueName As String, _ ' Name of value
ByVal lpReserved As Long, _ ' Reserved, must be 0
lpType As Long, _ ' Registry data type constant
lpData As Any, _ ' By reference variable for data
lpcbData As Long _ ' Number of bytes of data written
) As Long
You can use java's JNI to invoke functions that are native to that platform, using a language like C.