We can. You can actually divide it up into three different accounts if you want. You can either have it done as a dollar amount (for example, "I want $50 each pay period to go to account X and the balance to go to account Z") or you can specify a percentage ("I want 25% of my pay to go to account X and 25% of my pay to go to account Z and 50% of my pay to go to account Y").
Since I went back to work part-time we decided that my pay would go into our savings account and become our "Fix up the House" fund.