Private Declare Function GetTempPath Lib "kernel32" Alias _
    "GetTempPathA" (ByVal nBufferLength As Long, _
    ByVal lpBuffer As String) As Long

Private Declare Function GetTempFileName Lib "kernel32" _
    Alias "GetTempFileNameA" (ByVal lpszPath As String, _
    ByVal lpPrefixString As String, ByVal wUnique As Long, _
    ByVal lpTempFileName As String) As Long

Public Function GetNewTempFile(strPrefix As String) As String' strPrefix can be whatever you want
    Dim strPath As String * 512
    Dim strName As String * 576
    Dim lngRetVal As Long
    lngRetVal = GetTempPath(512, strPath)
    If (lngRetVal > 0 And lngRetVal < 512) Then
        lngRetVal = GetTempFileName(strPath, strPrefix, 0, strName)
        If lngRetVal <> 0 Then
            GetNewTempFile = Left$(strName, _
            InStr(strName, vbNullChar) - 1)
        End If
    End If
End Function