VBA to find empty cells and populate from matched Id

[benntw]

I work in a program that tracks equipment. There are two categories of equipment, Main and Sub. Not all Main will have a Sub attached to it, but when there is a Sub attached it has the same Id as the Main equipment. The Main equip has the project number, task number, work date, start, stop time, etc. The sub equipment only has a few categories filled out. What I want to do is paste my exorted csv file into excel and run a VBA to search all columns and cells for matching Ids. Then put the information in the cells of the sub equipment to match the main equipment information. I cannot wrap my brain around how to search for Ids that match and populate empty cells with the same information where there is value in one and not the other. I hope this makes sense. Hopefully someone can help me out on this. Thank you.