Hi all, following the piece of advice, I tried to use tabulate but got an error message with the following code:
\starttext
\startcombination[1]{
\starttabulate[|r|l|]
    \NC c \NC centered      \NC \AR
    \NC l \NC left aligned  \NC \AR
    \NC r \NC right aligned \NC \AR
\stoptabulate
}{a}
\stopcombination
\stoptext

! Missing } inserted.

system          > tex > error on line 7 in file /tmp/test.tex: Missing  ...

 1     \starttext
 2     \startcombination[1]{
 3     \starttabulate[|r|l|]
 4         \NC c \NC centered      \NC \AR
 5         \NC l \NC left aligned  \NC \AR
 6         \NC r \NC right aligned \NC \AR
 7 >>  \stoptabulate
 8     }{a}
 9     \stopcombination
10     \stoptext

<inserted text>
}
<to be read again>
\halign
<to be read again>
{
<inserted text>
\aligntab \tabl_tabulate_flush_indent \strut \alignmark \aligntab \alignmark \t
\tabl_tabulate_process ..._tabl_tabulate_preamble
                                                  \crcr \tabl_tabulate_inser...
l.7 \stoptabulate