VBA WinHttp no mapping character - vba

Question

Here is the source of a function I use get HTML code for further proccessing:
Public Function DownloadTextFile(url As String) As String
Dim oHTTP As WinHttp.WinHttpRequest
Set oHTTP = New WinHttp.WinHttpRequest
oHTTP.Open Method:="GET", url:=url, async:=False
oHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
'oHTTP.setRequestHeader "Content-Type", "multipart/form-data; "
oHTTP.setRequestHeader "Content-Type", "text/html; charset=utf-8"
oHTTP.Option(WinHttpRequestOption_EnableRedirects) = True
oHTTP.send
Dim success As Boolean
success = oHTTP.waitForResponse()
If Not success Then
Debug.Print "DOWNLOAD FAILED!"
Exit Function
End If
Dim responseText As String
Debug.Print oHTTP.responseText
responseText = oHTTP.responseText
'Set fs = CreateObject("Scripting.FileSystemObject")
'Set a = fs.CreateTextFile("c:\testfile.txt", True, False)
'Set a = fs.CreateTextFile("c:\testfile.txt", True, True)
'a.WriteLine oHTTP.responseText
'a.Close
Set oHTTP = Nothing
DownloadTextFile = responseText
End Function
It works for most pages, but for some pages the responseText is No Mapping for the Unicode character exists in the target multi-byte code page.
Here is an example of web page for which the responseText is No Mapping for the Unicode character exists in the target multi-byte code page
http://bzp0.portal.uzp.gov.pl/index.php?ogloszenie=browser&action=search&rodzajzamowienia=B&rodzajogloszenia=1&aktualne=1&datapublikacji_rodzaj=5&iloscwynikownastronie=20&offset=20
and here is a suspicious character that can't be encoded (screenshot from google chrome):
http://imageshack.us/photo/my-images/585/errsource.png/
From time to time on same website but for different search result this function does not generate error, but then, the HTML source in immidiate window is like ?????? ...
Any ideas how to make it work?

Answer 1

Solution that worked for me:
responseText = VBA.Strings.StrConv(oHTTP.ResponseBody, vbUnicode)
Note the use of ResponseBody instead of ResponseText

Answer 2

Try to use StrConv:
DownloadTextFile = VBA.Strings.StrConv(responseText, vbUnicode)
vbUnicode: Converts the string to Unicode using the default code page of the system. (Not available on the Macintosh.)