I would do this with two quota questions. The first quota question has just three cells: code 1, codes 2-3, and codes 4-6. Then skip respondents who fit into the first cell to the second quota question.
In the second quota question, add two cells. Set them both to always qualify and give them large but proportionate limits. For example, 82,000 for the first cell and 18,000 for the second cell. Finally, set this second quota question to "Least Fill (Percentage)."
About 82% of code 1 respondents should make it into one cell, the rest will make it into the other.