After reading around, I actually found a solution. This might be not very elegant, but it works fine. I am just posting this in cases anyone else is interested. For "RTF_file path", give the file path for the RTF file.
fid = fopen(RTF_file_path);
%get each line in the file and run WHILE loop until you read the line with
%'cells_QC'
tline = fgetl(fid);
while ischar(tline)
desired_line = strfind(tline, 'cells_QC');
%If the desired line is found break the loop
if desired_line
break;
end
tline = fgetl(fid);
end
%Find beginning and end of the row_vector
vector_left = find(tline == '['); vector_right = find(tline == ']');
vector = tline(vector_left:vector_right);
%Convert from string to vector
cells_QC = str2num(vector);