Hey Ali,
I hardly recommend you to format your data as a table.
For extracting a specific Line use find():
For Example:
Energy R Z Th Result Rel Error
1.000E+36 5.000 6.750 0.500 2.14157E-17 9.41189E-01
Energy=1;
R=1;
Z=1;
Th=1;
Result=2;
RelError=3;
%myTable is your readIn Data
YourLine=find(myTable{:,1}==Energy&myTable{:,2}==R&myTable{:,3}==Z&myTable{:,4}==Th,&myTable{:,5}==Result&...
myTable{:,6}==RelError);
if(isempty(YourLine)==0)%just to prevent crashes if a line can not be found
%do something further
end