How to create an Index based on my smallcase holdings?

Hello,

So, I have bought a couple of smallcases and I noticed that small case already indexed it to 100. From my investments screen I can easily see which of smallcases is up and by how much. Now is it possible to do the same for all of my smallcases, i.e. create a combined index weighted according to weightage of stocks in my portfolio? When I rebalance, it should reflect that too.

Please let me know if I don’t make sense, I am still a beginner.