How to process a specific list of incomplete additions in Assets?

Summary:

We are planning to send 150,000 assets into Fusion Fixed Assets and need to be able to search for and process specific batches of assets.

Content (required):

Prepare All just selects a random? first? 5,000 assets and loads it into the spread sheet.

Prepare Source Lines allows us to search for the assets but then selecting Prepare All again loads a random 5,000 assets.

What is the correct method to select say 2,000 assets from a single category or type and only process those assets via the spreadsheet loader?

Version (include the version you are using, if applicable):

22B

Code Snippet (add any code snippets that support your topic, if applicable):