OLEObjects

Thank you so much for the response Jen, I will Explain this in as much detail as possible.

I have a spreadsheet, which I will refer to as the "Form", is used for reconciling different documents such as receipts, invoices, credit notes. The people that use the Excel spreadsheet input the data from those documents and that's as far as their excel knowledge goes. So the Form must be user friendly to anyone no matter their excel knowledge. My job is to improve this form without changing its primary function or the premise of the form.
Meaning I'm focusing on simple protected functions and simplifying/automating the process of inputting generic information. One very common is the two codes people generally input (or in most cases forget to input).
I will focus mainly on one which is a descriptor code. Like in my first post about Pizza, I have a source of data which is secured in another sheet on the excel document I currently have a data validation list connected to the source to create a drop down of the different codes. The main issue is upon talking to the users of this form the main issue is they forget which code relates to which descriptor. I want to not have the users having to switch between the sheets I want it so the descriptor is beside the code. From my current knowledge I understand this is doable with comboboxes - as I've done similar for a single combobox in a Userform totally unrelated to this document.
However, there is between 100-150 lines of inputted data each row would require a combobox for primarily the descriptor code. My experience with comboboxes in excel sheets is after just a handful in a spreadsheet with automatic functions it can start to slow and become relatively large. The document must be able to be inputted on slower systems such as an old model laptop. Be uploaded to and downloaded to and from a system called Box before being uploaded to a in house accounting system - once I clean and audit said data.
A little googling said I'd be able to achieve this using a single combobox that appears at the selected location, when you click on a specified predefined range of cells. Trying to pull on this string connected to OLEObjects and trying to find material to elaborate on how to code around them I reach dead ends or unhelpful information.

As for my knowledge assume my current knowledge is that of a basic level. With the capacity to navigate the more complex coded lines and reverse engineer them as long as I'm provided with a sheet said code works on or a simplified description of how the code works, so I can replicate and test it. My knowledge on some very specific errors is what I was told is advanced but the method I take to learning is very targeted so although I can operate some more complex things I know little of the basics for most other areas, this method provides the fastest results for me in producing a finished product.

I hope this is detailed enough, excuse my lack of jargon.
If I can be provided with a starting point around this topic with enough information on it I should be able to go from there and build my own (potentially less efficient) but working code - I can work on improving it after I get it to operate correctly.

Kindly,
Alfie