[Closed] assign mat id's to objects

hey,

scenario: 10 boxes in one scene, 1 multi/sub object material with 10 materials inside it.

I want to be able to select the 10 boxes in the viewport and then it assigns a material id to it.
Therefore I have 10 objects with 10 different materials on it.

I got as far as making a script that pulls images in from a directory and puts them into
a multi sub object shader but I’ve hit a wall with this one.

Any help would be appreciated!