Required Electromagnet Design Calculation

dear sir

i want to make a electromagnet for my project for that i need some excel sheet or some kind of calculator or software that can help me in making electromagnet of my desire parameters.

100 mm length 10 mm diameter of core soft iron or steel.

voltages 5 to 12 dc variable.

maximum dia of coil is 30 mm.

project details are.

i have two NeFeB magnets of south poles toward each other at a distance of 140 mm. electromagnet is in between them at 20mm separation each side. i have to give to and fro motion to electromagnet by reversing the polarity. minimum separation between electromagnet and permanent magnet is made. it can not stuck.

what i need how much turns required , what is gauge of wire, and what is field strength at 5vdc and at 12 vdc. current should not increase more then 1.5 amp.

thanks