On an IOS ( Native ) switch , you can simply create an L3 port.
interface
ip address x.y.z.w
On CatOS , just pick a random unused vlan , say 999 , just for the EIGRP peering purpose.
Here are the steps you will have to follow.
1. Create that vlan --> set vlan 99
2. Put a L2 port that connects to the IOS switch in that vlan. set vlan 999 m/p
Make sure that is the only port in the switch that carries that vlan.
3. Go to the MSFC and create SVI 999.
int vlan 999
ip address
Now you are ready to peer this vlan 999 with the L3 port on an IOS switch over EIGRP.
thanks
Salman.