Hello!
After further checking up on the problem I managed to get the right solution - I think.
Having instantiated the CSplitterWnd panes, I can actually get a pointer to their views using
something like in the CChildFrame window:

CWnd* CurFileView=m_wndSplitter.GetPane(1,0);

Then I can address the CCurrentFileView view created as a CRUNTIME_CLASS and the problem seems to be solved!

VictorN & ADSOFT: thank you for contributing.
Best regards
Gustav