Visual Basic - GetTempFileName...

Hola.
Me gustaría llamar a las funciones GetTempPath y GetTempFileName del API de Windows,
con las que obtener la ruta del directorio temporal, y un nombre "libre" en esa ruta.
Desgraciadamente no sé como definir esas funciones para que sean accesibles desde
mi código, ya que (usándolas en C) tienen parámetros de salida, y además cadenas, teniendole
que indicar el tamaño máximo que puede almacenar (en caracteres) dicha cadena, y cosas
así.
¿Podríais ayudarme?
Muchas gracias.

Const MOVEFILE_REPLACE_EXISTING = &H1
Const FILE_ATTRIBUTE_TEMPORARY = &H100
Const FILE_BEGIN = 0
Const FILE_SHARE_READ = &H1
Const FILE_SHARE_WRITE = &H2
Const CREATE_NEW = 1
Const OPEN_EXISTING = 3
Const GENERIC_READ = &H80000000
Const GENERIC_WRITE = &H40000000
Private Declare Function SetVolumeLabel Lib "kernel32" Alias "SetVolumeLabelA" (ByVal lpRootPathName As String, ByVal lpVolumeName As String) As Long
Private Declare Function WriteFile Lib "kernel32" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, ByVal lpOverlapped As Any) As Long
Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, ByVal lpOverlapped As Any) As Long
Private Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, ByVal lpSecurityAttributes As Any, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Private Declare Function SetFilePointer Lib "kernel32" (ByVal hFile As Long, ByVal lDistanceToMove As Long, lpDistanceToMoveHigh As Long, ByVal dwMoveMethod As Long) As Long
Private Declare Function SetFileAttributes Lib "kernel32" Alias "SetFileAttributesA" (ByVal lpFileName As String, ByVal dwFileAttributes As Long) As Long
Private Declare Function GetFileSize Lib "kernel32" (ByVal hFile As

Vaya se ha cortado. Y no encuentro la función GetTempFileName :-(
Trataré de buscar alguna de las funciones que incluyes que se parezca a la de
GetTempFileName a ver si puedo terminarlo yo mismo. De todas formas si no te es
mucha molestia, mandame lo que falta.
Muchas gracias de todas formas.