Private Declare Function MultiByteToWideChar Lib "Kernel32" (ByVal CodePage As Long, ByVal dwFlags As Long, ByVal lpMultiByteStr As Long, ByVal cchMultiByte As Long, ByVal lpWideCharStr As Long, ByVal cchWideChar As Long) As Long
Private Declare Function WideCharToMultiByte Lib "Kernel32" (ByVal CodePage As Long, ByVal dwFlags As Long, ByVal lpWideCharStr As Long, ByVal cchWideChar As Long, ByVal lpMultiByteStr As Long, ByVal cchMultiByte As Long, ByVal lpDefaultChar As Long, ByVal lpUsedDefaultChar As Long) As Long
Private Declare Function GetACP Lib "Kernel32" () As Long
Private Const CP_ACP = 0 ' default to ANSI code page
Private Const CP_UTF8 = 65001 ' default to UTF-8 code page
'--------------------------------
' AToW
'
' ANSI to UNICODE conversion, via a given codepage.
'--------------------------------
Public Function AToW(ByVal st As String, Optional ByVal cpg As Long = -1, Optional ByVal lFlags As Long = 0) As String
  Dim stBuffer As String
  Dim cwch As Long
  Dim pwz As Long
  Dim pwzBuffer As Long
  If cpg = -1 Then cpg = GetACP()
  pwz = StrPtr(st)
  cwch = MultiByteToWideChar(cpg, lFlags, pwz, -1, 0&, 0&)
  stBuffer = String$(cwch + 1, vbNullChar)
  pwzBuffer = StrPtr(stBuffer)
  cwch = MultiByteToWideChar(cpg, lFlags, pwz, -1, pwzBuffer, Len(stBuffer))
  AToW = Left$(stBuffer, cwch - 1)
End Function
'--------------------------------
' WToA
'
' UNICODE to ANSI conversion, via a given codepage
'--------------------------------
Public Function WToA(ByVal st As String, Optional ByVal cpg As Long = -1, Optional ByVal lFlags As Long = 0) As String
  Dim stBuffer As String
  Dim cwch As Long
  Dim pwz As Long
  Dim pwzBuffer As Long
  Dim lpUsedDefaultChar As Long
  If cpg = -1 Then cpg = GetACP()
  pwz = StrPtr(st)
  cwch = WideCharToMultiByte(cpg, lFlags, pwz, -1, 0&, 0&, ByVal 0&, ByVal 0&)
  stBuffer = String$(cwch + 1, vbNullChar)
  pwzBuffer = StrPtr(stBuffer)
  cwch = WideCharToMultiByte(cpg, lFlags, pwz, -1, pwzBuffer, Len(stBuffer), ByVal 0&, ByVal 0&)
  WToA = Left$(stBuffer, cwch - 1)
End Function

'Use this to encode before you send...
Function EncodeUTF8(ByVal cnvUni As String)
  If cnvUni = vbNullString Then Exit Function
  EncodeUTF8 = WToA(cnvUni, CP_UTF8, 0)
End Function

'Use this to decode received strings...
Function DecodeUTF8(ByVal cnvUni As String)
  If cnvUni = vbNullString Then Exit Function
  cnvUni = WToA(cnvUni, CP_ACP)
  DecodeUTF8 = AToW(cnvUni, CP_UTF8)
End Function