Concatenate Columns value ordered

Database

Concatenate Columns value ordered

Hi,
I have a table that looks like this:

Column1 Column2 Column3
800 900 200
500 300 40
100 600 150

and I would like to concatenate Column1, Column2, Column3 in a list that is order by the values of three columns:

Result
200,800,900
40,300,500
100,150,600

Any suggestions on how to do it in Teradata SQL (TD 15.10)?

Thanks for your help

Marco