string str1$ = __lastwks$;

range r1 = [str1$]6!11; //the target column
range r2 = [str1$]6!5; //the source column (the values must be summarized row by row)
range r3 = [str1$]6!10; //the condition column (a one in this column sets the sum to zero)

r1 = {1: r2.GetSize()}; //the worksheet will have about 100000 rows
r1 = 0;

int jj = 0;
break -b "Count something";  
break -r 0 r1.GetSize();

//iterating through all rows seems to be very slow...
for (ii=2; ii<r1.GetSize(); ii++)
{

    if(r3[ii] == 0)
    {
        r1[ii] = r1[ii-1] + r2[ii];
    }

    if(r3[ii] == 1)
    {
        r1[ii] = 0;
    }

    jj++;
    if(jj == 1000) 
    {
        jj = 0;
        break -p ii;
    }    
} 

break -end;

break -b This is the caption for the dialog box;  
break -r 0 100;  // the range of values will be 0 - 100 
for (ii = 0; ii <= 100; ii=ii+5) // Show every 5 percentage 
{
      break -p ii;   // the current value is ii
      csetvalue col:=col(a) formula:="i";// Put your code here
      csetvalue col:=col(b) formula:="cos(col(a))";
      //sec -p .1;   // Delay to simulate executing code
};
break -end;  // done, close the dialog box

type -q  some string

"-q"

some string