OK, just a little bit more. There is a questionnaire form for James Hammond in the NA [WO 344/380/1] - unfortunately it contains very little that is new.
2979826 Private Hammond, James 2nd Battalion Argyll and Sutherland Highlanders
DoB 1/5/18
Date of enlistment: 4/5/36
Address: 116, Ferguslie Park Avenue, Paisley, Renfrewshire
Place of Capture: Klang [F. M. S.] on 10/4/42
And that's all there is. Men were not ordered to fill in the forms, the authorities knew only too well what they had been through and, quite frankly, some of them were in no position to give much more that name, rank and number.
However:
The date of enlistment confirms that your man was a regular;
Klang would appear to be Port Klang, which is on the Malay peninsula and the date of capture is a good few weeks after the fall of Singapore, so there may be a story there.
I did also find in the same file the questionnaire of another man who was in the 2nd Battalion A & S Highlanders and he was captured at Singapore on the date that it fell. He listed some of the camps that he had been held in:
Changi
Ban Pong
Chunkah
Takanoon
It would be fairly usual to keep men from the same unit together - so it may well be the case that your man was in one or more of those camps. He would almost certainly have been in Changi, which was the main holding camp in the immediate aftermath of the surrender. The FEPOW site should help you identify a few more details.
Hope that helps
jds1949