I am debugging a huge application (which, among others, integrates in Excel
and other Office products) for a bug in which Copy-Paste doesn't work as
expected.

Here's what the application does:
- Added its window to the chain of clipboard viewers
- On "Copy" (when it receives WM_DRAWCLIPBOARD), it passes control to a
COleDataSource-derived class, which then retrieves a data object from the
Clipboard through OleGetClipboard(), and then iterates through the formats
supported by the data object.
- If the formats it supports are Biff8, Embedded Object, Link Source, or
Link Source Descriptor - which were all registered with
RegisterClipboardFormat() - then it fills in, in the proper format, the data
into the provided STGMEDIUM.
- Then, on "Paste", Excel asks (the COleDataSource-derived class, by means
of OnRenderData()) for the formats: Link Source Descriptor, then Link
Source, and Link Source Descriptor again, and the application fills those
into the provided STGMEDIUMs again.
- But after the paste is done, what actually got pasted by Excel is a shape
object (with the round knobs to rotate and resize it). Although in the
formula bar I can see the correct content (a formula containing a moniker to
the cell that I copied in the first place) and the text in the shape object
is the text that was linked from a different workbook's cell.

So the BIG question is: Why does Excel paste the object as a shape, although
the data that was rendered was fine, and in the format required by Excel?
What I want is for Excel to paste the formula in the cell, and then the
evaluation will work (as it works now) and fill the content of the cell with
the result of the evaluation.

Anybody who has an answer? I would greatly appreciate any thought on this
issue, since it has made me tired with research.