Because a BMS macro is an assembler language statement, you have to follow assembler syntax rules. We do not try to explain those in full here; you can find them in Assembler H Version 2 Application Programming Language Reference manual. Instead we give you a set of rules that work, although they are more restrictive than the actual rules.
This is how you write DBCS initial values:
GINIT='<D1D2D3D4D5>',PS=8,LENGTH=10
INITIAL='<D1D2D3D4D5>',SOSI=YES,LENGTH=12
XINIT='C4F1C4F2C4F3C4F4C4F5',PS=8,LENGTH=10
XINIT='0EC4F1C4F2C4F3C4F4C4F50F',SOSI=YES,LENGTH=12
INITIAL='ABC<D1D2D3D4D5>def',SOSI=YES,LENGTH=18
XINIT='C1C2C30EC4F1C4F2C4F3C4F4C4F50F848586',SOSI=YES,LENGTH=18
If you have stopped within a DBCS string, put an SO character in column 16 of the next line and resume in 17; otherwise just resume in 16, thus:
GXMPL1 DFHMDF POS=(02,21),LENGTH=20,PS=8,GINIT='<D1D2D3D4D5D6>******
<D7D8D9D0>'
IXMPL1 DFHMDF POS=(02,21),LENGTH=23,PS=8,INITIAL='abc<D1D2D3D4>ABC**
DEFGHIJ'
You cannot use extended continuation with XINIT; use the rules described in Step 7.