Quite how much do we know about this? How much of it is DWM's speculation? How much is the author's imperfect memories? Someone needs to dig up DWM 255 and check.
Therefore, its known narrative elements are not a part of the Doctor Who universe as we, on this Wiki, choose to define it. It may have been the basis for a similar story in another medium, however — and that story may indeed be valid.
According to the DWM 255 article, the story would have featured the return of the First Rani and would have been set in a university where she was posing as vice chancellor. A similar plot would later appear in the Sixth Doctor audio story, The Rani Elite. In DWM 255, it mentioned that the episode would have concerned stopping "A Biological Computer Virus" from taking over the world's computer systems. Other characters thought have been featured in the story were Brigadier Winifred Bambera and Sam Tollinger.
- DWM 255 - Article: What if?