multiple fit

Hi, I am using Scilab for first time. I have this data file (ep.txt). The first column is x followed by 5 y columns. I want to fit each column with y=a+b*(x-c)**2. Is it possible to do it simultaneously (to find a,b,c for all 5 y columns at a time) or should I try one y column at a time. In that case can anyone suggest me the command lines.
Thank you.