How to define custom length and width of non-EM lumped components in their layouts?

I'm trying to a make a custom cell of lumped components such as capacitors. But this cells will have the pad information.
My final goal is to use the symbol of the custom cell for schematic simulation and custom-layout for co-simulation.

So i've made a simple capacitor model of 0603 package. i'm passing capacitance value and substrate informtion as a parameter. for now the pad size is fixed. later i'm planning to parametrize them too.

https://preview.redd.it/yqsjh7gj6h4e1.png?width=897&format=png&auto=webp&s=18d11d430f6237df65df06623a6707f3777785d8

I've created the same symbol for the custom capacitor cell.

https://preview.redd.it/olvwewel6h4e1.png?width=1321&format=png&auto=webp&s=de0e0b7785cedf07247b730bf1848aaefd965664

now while defining the layout of the cusotm cell, the capacitor is always having a default non-EM footprint. This is causing issues during co-simulation.

https://preview.redd.it/m727loqm6h4e1.png?width=1222&format=png&auto=webp&s=00259e0087f1fa9489de221f8de6dee6fee746de

The issue is here. The cell is being used in a different cell. In the layout the custom_capacitor_cell is having the following (C3) footprint. Since the actual capacitor (non-EM lumped), which is shows by box-with-cross, is touching the left pad only, in the em-cosim view only a single port is begin created.

https://preview.redd.it/x9ypc48o6h4e1.png?width=943&format=png&auto=webp&s=756ca21eb6ecdcff6541d1cee882390c3c21e513

Only if i could increase the length of the non-EM model to match the gap size, this issue can be fixed with very little involvement.

https://preview.redd.it/jo2bmxap6h4e1.png?width=827&format=png&auto=webp&s=2680dee6c685b1fe6268f5d7665ad0fa6f8fbe34

How do I do this>>

Or should i follow some different strategy?

~Thanks.