Accessing CreateUserWizard's "Create User" Button

 How can I access this button in code behind?
I have selected "Customize Create User Step"  - vecause I need to modify fields.
If I also convert to "StepNavigationTemplate" in source I get:
 
<asp:Button ID="StepPreviousButton" runat="server" CausesValidation="False"
CommandName="MovePrevious" Text="Previous" />
<asp:Button ID="StepNextButton" runat="server" CommandName="MoveNext"
Text="Next" /> But I don't see this button on the control!
If I also enable "CustomNavigationTemplate&q ...