Just assign the Tab order:
Thusly...
<form>
<input type="text" name="TextBox1" tabindex=1 /><br />
<input type="text" name="TextBox2" tabindex=3 /><br />
<input type="text" name="TextBox3" tabindex=2 /><br />
</form>
As you see it goes from 1 to 3 to 2.
Also, see
This[
^]
article from the CP Archives