I can't tell you what you did wrong, because you decided not to post what you have tried. That meant I had to write your code from scratch. I resisted the urge to extract a different parameter and let you modify the code to get to the proper result.
x=webread('https://markets.ft.com/data/funds/tearsheet/summary?s=LU0323048693:EUR');
pat='<th>Ongoing charge</th>';
ind1=strfind(x,pat);ind1=ind1(1)+numel(pat);
ind2=strfind(x,'</td>');ind2(ind2<ind1)=[];ind2=ind2(1);
x((ind1+4):(ind2-1))
