Hello Team
I want to use my custom field in “Activities Sub Panel” in place of “Assigned User” Accounts Modules is this possible ?? Which file should i edit i want only one field to replace and use my own.
This can be done via studio, navigate to accounts and then subpanels, click on the subpanel you want to make changes to and drag what fields you want / dont want
hhmm 
I don’t think this will work for the “aggregated” subpanels, History and Activities.
For these I think it takes a change to the subpaneldefs.
You could try this but it’s going to be a bit tricky:
Pay attention to that last comment, where it corrects the paths (subpanels, not subpanel)
This link is not working sir.
Yes it is, it just takes a long time to load, it’s a web archive, cold storage. Just wait, and refresh if necessary, eventually the page appears (with some broken formatting)