Hi,

i think it will be difficult to solve it in that way. If you put the 5 fieldnames into one string, that will not result in 5 cells. What you can do, is to make 5 variables which you call then with a tab-separated list.
Your table has in fact 5 columns. Alas it does not work to use \setupTABLE to organize this, because ConTeXTt expects the nx=5 after the  \bTD. Waht you can do, is to prepend the entry's of the first, second and last row with [nx=5]

See attached example.

Willi