Indeed, see Volume 1, section 2.4 (Multilinked Structures). Page 426 has the example of the statement “MOVE CORRESPONDING DATE OF SALES TO DATE OF PURCHASES”, which, if I understand correctly, means something like “for each field foo in Purchases.Date, copy Purchases.Date.foo into Sales.Date.foo”.
The discussion is in the context of what kinds of data structures would be needed to compile such statements, which I guess makes sense considering that the original publisher offer for TAOCP was to write about everything a programmer would need to know to write a (60s-era) compiler.
(Coincidentally: I've started attending an online meetup that someone is running for reading TAOCP—we usually read about four pages in the two hours—and this is the very topic that we're going to read tomorrow.)
This horrifies me on several levels, though I suppose it could be considered a sort "cast to a superclass".
It is also relatively rare for new languages cite Cobol as an inspiration for any of their features.
Cobol has a feature whereby dissimilar structures can be assigned. The structure members which have the same names are identified between the structures and the data is moved accordingly. Or something like that. A programming language which has such a thing could claim to have had that inspired by Cobol.
If I ever add that to TXR Lisp, I will be sure to drop a Cobol reference into the documentation.
I might have learned about this via Knuth; I think there is a mention of it in some passage in TAOCP.