I can't think of one either.
Let's list the nations that have a 47 anything (47*, 47 or 47L).
French: Both 47 and 47L. Though the French had done some pioneering work on HEAT, I have never heard of a HEAT round.
British: Though not in British colours, the Vickers 6 Ton was British and never had a 47* HEAT round, so the various Chinese, Bulgarian or Polish ones are out.
German: Just the 47L as mounted on the PzJg I and as the Axis Minor (Slovak) 47L AT gun. This might have been what they were thinking about.
Japanese: Both as a 47L tank and AT gun, again I have not heard of a HEAT round.
Belgian: Never heard of a HEAT round.
Italian: The Italians had a HEAT (Effetto Pronto) round for their 47 and 47L tank and AT guns from '42, but what little I have found out indicates it's a calibre round, IE 47mm in diameter. That would only give penetration in the 10-12 TK range. Some at least used in the desert, some said the users were happy, some that it was no better than AP rounds in penetration except at distance. See: http://www.comandosupremo.com/forums/topic/343-47mm-4732-and-tank-gun-ep-effeto-pronto/
ASL in my opinion rightly ignores it. Ditto for the Axis & Allied Minor 47 guns of the same parentage (Böhler).
My guess is that the ASL designers had the German 47L in mind. This was a Czechoslovak AT gun and I would be surprised if they did not develop an oversized spigot type round that fitted over the muzzle. The Germans did such rounds for the 37L AT, 50L AT and the 150* INF, the later more a anti-bunker round than an AT round. They went with normal calibre rounds for their 75 and 105 HEAT rounds. As the 47L as mounted on the PzJg I only lasted in German service from '40-'41, I would be surprised if many rounds were produced and might have ended up in Slovak hands. A TK of 26 implies an over calibre spigot type round.