Attracting force between Crystal and Solvent

Hi,

i am trying to figure out if a certain molecule fits in the lattice of a crystal (and in which way). I thought about simulating the crystal and using the molecules as a solvent. Defining an attracting force between the crystal and solvent should deliver the desired effect. Did someone do something similar and can explain me what they did? Is this method adequate or are there some obstacles i didnt think about.

Sincerely,

Momin Ahmad