I don’t think it does support this in SBCS. You May need to look at changing your CCSID to one that supports DBCS. You will also need a printer that supports DBCS.
Here are the CCSID’s that IBM shows for Vietnamese:
CCSID (decimal) CCSID (hex) Name
1129 0469 VIETNAMESE ISO8
1130 046A VIETNAMESE EBCDIC
1163 048B VIETNAMESE ISO8
1164 048C VIETNAMESE EBCDIC
See http://www-01.ibm.com/software/globalization/ccsid/ccsid_registered.jsp for more information.
Vietnamese is not DBCS. It’s SBCS just like 37, 500, etc. It does though have a different character set and code page.
Before continuing, do you have a workstation configured for Vietnamese? That will simplify things. If you only have say English workstations then you can still print out Vietnamese, it will just be a bit more work (confusing).