Idris Samawi Hamid ادريس سماوي حامد schrieb:
> \setuphead[chapter]   [conversion=R]
>
> \setuplist[chapter][width=2.8em]
>
> \definecombinedlist
> [content]
> [chapter]
> [level=chapter,
> alternative=c,
> numberalign=flushright]

Use \setuplist to change the numeralign setting, you need also a 
distance value.

\setuplist
   [chapter]
   [alternative=c,
    width=2.8em,
    distance=1em,
    numberalign=flushright]

The attached file shows which values are valid for \setupcombinedlist.

Wolfgang