How do I retrieve data from specific fields in 3 different lists, aggregating them into 1 new list?

Okay SharePoint lovers, I think I need someone who can do some programming behind the scenes (I know I can’t!).

This is what I need: I’m trying to gather “field data” from multiple sites (or sub-sites). I’ve read about the Content Search Web Part but am having no luck with that – I think it’s because I’m looking to aggregate specific fields. For example:
I have three sites, all with lists:

Site A
Company Name
End User
Tool Name
Status

Site B
Company Name
End User
Part Number
Warranty Expiration

Site C
Company Name
Delivery Date
Value

From these 3 sites, I’d like to have Company Name as the key field (for lack of a better term), to a new list on a new page containing: Company Name (key field) Part Number (from site B) Warranty Expiration (from site B) Delivery Date (from site C).

Can anyone help??? Doing any sort of back-end programming is beyond my skill level.