Option Explicit
 
'// kernel32.dll
Private Declare Function MultiByteToWideChar Lib "kernel32.dll" (ByVal CodePage As Long, ByVal dwFlags As Long, ByRef lpMultiByteStr As Any, ByVal cchMultiByte As Long, ByVal lpWideCharStr As Long, ByVal cchWideChar As Long) As Long
Private Declare Function WideCharToMultiByte Lib "kernel32.dll" (ByVal CodePage As Long, ByVal dwFlags As Long, ByVal lpWideCharStr As Long, ByVal cchWideChar As Long, ByRef lpMultiByteStr As Any, ByVal cchMultiByte As Long, ByVal lpDefaultChar As String, ByVal lpUsedDefaultChar As Long) As Long
 
'// Const
Private Const CP_UTF8                           As Long = &HFDE9 '65001
 
'// Enum
Public Enum CONV_TYPE
    Unicode = vbUnicode
    UTF8 = vbFromUnicode
End Enum
 
'// Function
Public Function StrConversion(ByRef vEntry As Variant, eConv As CONV_TYPE) As Variant
Dim lRet                                        As Long
Dim lLen                                        As Long
Dim lBuffer                                     As Long
Dim sBuffer                                     As String
Dim bvOutput()                                  As Byte
 
    On Error GoTo Exit_
 
    If eConv = Unicode Then
        lLen = LenB(vEntry) \ 2
 
        If lLen Then
            lBuffer = lLen + lLen + lLen + 1
            ReDim bvOutput(lBuffer - 1) As Byte
 
            lRet = WideCharToMultiByte(CP_UTF8, 0, StrPtr(vEntry), lLen, bvOutput(0), lBuffer, vbNullString, 0)
 
            If lRet Then
                ReDim Preserve bvOutput(lRet - 1) As Byte
                StrConversion = bvOutput
            End If
        End If
    Else
        lLen = UBound(vEntry) + 1
 
        If lLen > 1 Then
            lBuffer = lLen + lLen
            sBuffer = Space$(lBuffer)
 
            lRet = MultiByteToWideChar(CP_UTF8, 0, vEntry(0), lLen, StrPtr(sBuffer), lBuffer)
 
            If lRet Then
                StrConversion = Left$(sBuffer, lRet)
            End If
        End If
    End If
 
Exit_:
End Function