I build several files by using the cut command to grab select fields(columns) from a really bid csv file. Each file is one column of data. I then put them together using paste command. Here is the code built in tcsh:

cut -d , -f 1 some.csv > 1.csv
cut -d , -f 10 some.csv > 10.csv
paste 1.csv 10.csv > combined
rm 1.csv
rm 10.csv

Here is my Q? This leaves me with a data file, "combined" that is tab delimited (about 6 fields, no header row). I want it to be be a csv, how can i find/replace tab-stops with commas within the file?