Sorry, but I have that one already. And no, what I think I remember is more like a guide telling which COBOL statements are native-only (and what their manage-code counterpart is, if any), which have variations for use in managed code, and which features or aspects of a COBOL statement's implementation are restricted in managed code.
Things like when-and-or-if PROGRAM-ID has to be replaced with CLASS-ID, or what happens to DISPLAY UPON CONSOLE and SYSOUT redirection? The information which is probably scattered throughout the online product documentation, but would be more useful (to me) if it were available in a consolidated native-to-conversion "cook book" style of document.
Still not ringing a bell for anyone, or is my desire/hope for a quicker/easier way conspiring with my memory to lie to me?