Thanks Ziad,

I tried the command line in two ways, and neither of them provide a two column output.
When I run it as
ConvertDset -add_node_index -i_niml -o_1Dp -prefix Oorizfavored -input lh.1.poscor.mcnemar.clust_ClstMsk_r3.1_a247.0.niml.dset

I get a 1-col output with only the ROI nums, sans vertex nums, and the message:
Notice SUMA_PopulateDsetNodeIndexNel:
Dset has node indices. Will not alter list.

When I run it without the "-add_node_index" flag, I get the same thing.

Below I pasted what I do in shell and "R" to get the
ROInum, Vertexnum
representation. I'd be glad to send the dset file in question by email if helpful.

Cheers,
Oori

Shell:
cat $x | grep "^[[:space:]][[:digit:]]" > FOR-R."$x"

R:
current.clustmask <- "FOR-R.lh.1.poscor.mcnemar.clust_ClstMsk_r3.1_a247.0.niml.dset"
clust.table.initial <- read.table(current.clustmask)
num.entries <- length(clust.table.initial[,1])
# align the ROI category values with the vertex values
aligned.df <- data.frame(clust.table.initial[1:(num.entries/2),1], clust.table.initial[((num.entries/2)+1):num.entries, 1])

This, in R, gives the 2-column format.