Dc Motor and Stepper In the same program

Can some one help me with a code.
What I have.
-L293D Motor Control Shield Motor
-Arduino UNO
-12V Dc Motor
-Stepper motor (Mercury motor. SM-428YG011-25)
-12V power

What the code is suppose to do:
Control the stepper motor left and right with pushbuttons then have another button to actuate the Dc motor forward x amount then backwards same amount.

For some reason I cant get both motors to run in the same program .

Hard to help without knowing the exact shield (of several) that you have, how the motors are conneted to it and the code that have tried Did you read all of the the how to use this forum-please read stickies?

What is the stall current spec of the DC motors?

Why not get a specialized stepper motor driver such as a Pololu A4988?

Stepper Motor Basics
Simple Stepper Code