Could you just do something like this:

if invdet.aged eq "C" move ntotal to vdata[iRow][0]
else if invdet.aged eq "N" move ntotal to vdata[iRow][1]
else if invdet.aged eq "1" move ntotal to vdata[iRow][2]
else if invdet.aged eq "2" move ntotal to vdata[iRow][3]
etc.