another way than iterare 5 times

Question

I have a string string1="11001";
I want to Check a checkListBox in each index step according to the "1" value of
the string1
to do that I shift the string1 five times to the right and compare
the excess value with "1" ,and if the value equals then I check
the ChecklistBox index accordingly
But I think this way is not fast because i have to iterate five times
is there a better way than this ?
Please give me the idea

thx
denny