How to apply at least option only to a particular bin in a coverpoint

In reply to sj1992:

break your coverpoint into two coverpoints

c2_1: coverpoint var_1 { 
  bins min = {0};
  bins max = {1023};
}
c2_2: coverpoint var_1 { 
  option.at_least = 10;
  bins other_val[10] = {[1:1022]};
}