Yep, it can be done, but there is a limit on the overall length.  I want to say it's
around 2000 chars, but can't recall precisely.  You build the mailto URL from your
strings/variables, something like this:

  Private Sub PrepareEmail(ByVal AddrTo As String, ByVal AddrCc As String, ByVal
Subject As String, ByVal Body As String)
     Dim Link As String
     Link = "mailto:" & AddrTo & _
            "?cc=" & AddrCc & _
            "&subject=" & Subject & _
            "&body=" & EscapeURL(Body)
     Call OpenDoc(Link)
  End Sub

The two helper functions there prepare the body text for use in a URL and actually
execute the link:

  Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA"
(ByVal hWnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal
lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
  Private Declare Function UrlEscape Lib "Shlwapi.dll" Alias "UrlEscapeA" (ByVal
pszURL As String, ByVal pszEscaped As String, ByRef pcchEscaped As Long, ByVal
dwFlags As Long) As Long

  Private Const URL_DONT_ESCAPE_EXTRA_INFO As Long = &H2000000

  Private Function EscapeURL(ByVal URL As String) As String
     ' Purpose:  A thin wrapper for the URLEscape API function.
     Dim EscTxt As String
     Dim nLen As Long

     ' Create a maximum sized buffer.
     nLen = Len(URL) * 3
     EscTxt = Space$(nLen)

     If UrlEscape(URL, EscTxt, nLen, URL_DONT_ESCAPE_EXTRA_INFO) = 0 Then
        EscapeURL = Left$(EscTxt, nLen)
     End If
  End Function

  Private Function OpenDoc(ByVal DocFile As String) As Long
     Dim nRet As Long
     ' Actually uses the default verb if available, and "open" otherwise
     nRet = ShellExecute(0&, vbNullString, DocFile, vbNullString, vbNullString,
vbNormalFocus)
     Debug.Print "ShellExecute: "; nRet
     OpenDoc = nRet
  End Function

Later...   Karl