Good find. Interesting even if not obviously useful.

VB's intrinsic controls' .Text, .Caption, etc. seem to go through OLE plumbing that looks at control.Font.Charset, so I'm not sure we can jigger things to make those work.

Code:
Option Explicit

Private Enum WINDOW_MESSAGES
    WM_SETTEXT = &HC&
End Enum
#If False Then
Dim WM_SETTEXT
#End If

Private Declare Function SendMessageA Lib "user32" ( _
    ByVal hWnd As Long, _
    ByVal wMsg As WINDOW_MESSAGES, _
    Optional ByVal wParam As Long, _
    Optional ByVal lParam As Long) As Long

Private Sub Form_Load()
    Dim F As Integer
    Dim SampleBytes() As Byte

    F = FreeFile(0)
    Open App.Path & "\sample.txt" For Binary Access Read As #F
    ReDim SampleBytes(LOF(F) - 1)
    Get #F, , SampleBytes
    ReDim Preserve SampleBytes(LOF(F))
    Close #F
    SendMessageA Text1.hWnd, WM_SETTEXT, , VarPtr(SampleBytes(0))
End Sub
Code:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
  <assemblyIdentity type="win32" name="Joeblow.Project1" version="1.0.0.0"/>
  <dependency>
    <dependentAssembly>
      <assemblyIdentity language="*" name="Microsoft.Windows.Common-Controls" processorArchitecture="X86" publicKeyToken="6595b64144ccf1df" type="win32" version="6.0.0.0" />
    </dependentAssembly>
  </dependency>
  <application>
    <windowsSettings>
      <activeCodePage xmlns="http://schemas.microsoft.com/SMI/2019/WindowsSettings">UTF-8</activeCodePage>
    </windowsSettings>
  </application>
</assembly>