Telegram - Send Document via VBS

Const URL = "https://api.telegram.org/bot"
Const TOKEN = "xxxxxxxxxx"
Const METHOD_NAME = "/sendDocument?"
Const CHAT_ID = "xxxxxxxxxx"
Const FOLDER = "C:\"
Const DOCUMENT_FILE = "file.txt"

Dim data, key
Set data = CreateObject("Scripting.Dictionary")
data.Add "chat_id", CHAT_ID

' generate boundary
Dim BOUNDARY, s , n
For n = 1 To 16: s = s & Chr(65 + Int(Rnd * 25)): Next
BOUNDARY = s & CDbl(Now)

Dim part , ado 
For Each key In data.keys
part = part & "--" & BOUNDARY & vbCrLf
part = part & "Content-Disposition: form-data; name=""" & key & """" & vbCrLf & vbCrLf
part = part & data(key) & vbCrLf
Next

' filename
part = part & "--" & BOUNDARY & vbCrLf
part = part & "Content-Disposition: form-data; name=""document""; filename=""" & DOCUMENT_FILE & """" & vbCrLf & vbCrLf

' read document file as binary

Dim doc
Set ado = CreateObject("ADODB.Stream")
ado.Type = 1 'binary
ado.Open
ado.LoadFromFile FOLDER & DOCUMENT_FILE
ado.Position = 0
doc = ado.read
ado.Close
' combine part, document, end
ado.Open
ado.Position = 0
ado.Type = 1 ' binary
ado.Write ToBytes(part)
ado.Write doc
ado.Write ToBytes(vbCrLf & "--" & BOUNDARY & "--")
ado.Position = 0

Dim req , reqURL 
Set req = CreateObject("MSXML2.XMLHTTP")
reqURL = URL & TOKEN & METHOD_NAME

With req
.Open "POST", reqURL, False
.setRequestHeader "Content-Type", "multipart/form-data; boundary=" & BOUNDARY
.send ado.read
MsgBox .responseText
End With

Function ToBytes(str)
    Dim ado
    Set ado = CreateObject("ADODB.Stream")
    ado.Open
    ado.Type = 2 ' text
    ado.Charset = "_autodetect"
    ado.WriteText str
    ado.Position = 0
    ado.Type = 1
    ToBytes = ado.read
    ado.Close
End Function