Hi. What is the problem you are trying to solve? How to answer your question depends a lot on the problem you are trying to solve.

The computer fuel pump relay energizes for a couple seconds when the ignition is turned to "On", and then requires "Ignition On" AND "Crankshaft Rotation" via the speed sensor signal in order to energize. Duplicating this function outside of the computer is not trivial. Changing this logic in the functionality can also create safety issues in the event of an engine stop while the ignition is still on, like in an accident, and would not be recommended.