Thanks to Pierre Bellisle!

just three functions:

'Clipboard IPC

#Include ""

Function MyFormat() As Long
     Local MyClipboardName As Asciiz * 20 'make this the same length as the name below
     MyClipboardName = "MyOwnClipboardFormat"                  
     Function    = RegisterClipboardFormat(MyClipboardName)
End Function

Function WriteMyClipBoard (ByVal Txt As String) As Long
 Local lpMem As Asciiz Ptr
 Local hMem  As Dword

 hMem       = GlobalAlloc(%GHND, Len(Txt) + 1)
 lpMem      = GlobalLock(hMem)
 @lpMem     = Txt
 GlobalUnlock hMem
 OpenClipboard 0
 SetClipboardData MyFormat, hMem
 Function = 1
End Function

Function ReadMyClipboard() As String
   Local CData As Asciiz * 256, ClipDataPtr As Asciiz Ptr
   OpenClipboard 0
   ClipDataPtr = GetClipboardData(MyFormat)
   Function = @ClipDataPtr
End Function

Function PBMain()
 If ReadMyClipboard <> "" Then Print "I found this on my clipboard " & ReadMyClipboard
 WriteMyClipBoard(" I'll just put this on my clipboard")
End Function