Working with multiple CSVs from Microsoft 365 Content Searches is a classic "regular user" hurdle. Those reports are massive, and keeping them aligned is a bit like trying to line up two different jigsaw puzzles.

To answer your specific question: No, a standard "Paste" will not respect hidden columns. When you paste a range of data into an Excel sheet that has hidden columns, Excel treats the hidden columns as if they aren't there for the purpose of the "drop." It will simply paste the data into the visible columns sequentially (A, C, D, etc.), skipping over the hidden Column B entirely. This usually results in your data being shifted and misaligned.

Here are the best "geek-approved" ways to handle this without losing your mind:

Option 1: The "Unhide, Paste, Re-hide" (The Safest Way)

Since you've already done the work of hiding columns in your XLSX, the most reliable way to ensure the data lands in the right "slots" is to temporarily bring them back.

1. Unhide everything: Select the whole sheet (the triangle in the top-left corner), right-click a header, and select Unhide.
2. Copy the data: From your second CSV, copy the rows without the header row (start at row 2).
3. Paste: Paste them at the bottom of your XLSX. Because all columns are now visible, "Subject" will go under "Subject," "Date" under "Date," etc.
4. Re-hide: This is the annoying part, but if you use the Grouping method (Shift + Alt + Right Arrow) I mentioned earlier, you can just click one button to hide them all again.

Option 2: The "Power Query" Move (The Pro Way)

If you are going to be doing this often (e.g., every time you run a new Content Search), Power Query is your best friend. It allows you to "stack" two files together based on their column names, regardless of what is hidden in your view.

1. Go to the Data tab > Get Data > From File > From Text/CSV.
2. Select your second CSV.
3. Instead of "Load," click Transform Data.
4. Use the Append Queries button to stack the second CSV onto your first one.
5. Excel will automatically match the column headers, so even if "Sender" is the 10th column in one and the 12th in the other, it will align them perfectly.

A Quick Warning on Content Searches

Since these are 365 Content Search reports, watch out for the "Unindexed Items" or "Summary" rows at the very bottom of the CSV. If you copy the whole file, you might accidentally paste those summary totals into your data rows, which will definitely mess up any filtering or analysis you do later.

It's a bit of a transition from raw data to a clean report, isn't it? Would you like me to walk you through how to use "Paste Special" to ensure you don't overwrite your cell formatting when you bring that CSV data in?

In theory, yes-if you select the whole sheet (or the columns surrounding the hidden ones) and press Ctrl + Shift + 0, it should unhide everything.

However, there is a huge "but" here that makes most Excel regulars pull their hair out.

The Windows "Gotcha"

In many versions of Windows (especially Windows 10 and 11), the keyboard shortcut Ctrl + Shift + 0 is actually intercepted by the operating system for switching keyboard layouts or input languages.

Because Windows "grabs" that key combination first, the command often never even reaches Excel. If you press it and nothing happens, that is exactly why.

If the shortcut fails, use these "Plan B" moves:

• The "Select All" Right-Click: 1. Click the Select All triangle (top-left corner of the grid).

2. Right-click any column letter header.
3. Select Unhide.

• The Alt Key Sequence: If you want a keyboard way that definitely works regardless of Windows settings, use the old-school menu shortcuts. Press these keys one after another (don't hold them down): Alt H O U L *(This stands for Home > Format (O) > Hide/Unhide > Unhide Columns)*.

One Quick Tip for your Content Search CSVs

Since those 365 reports often have 50+ columns and you're only interested in a few, you might find it easier to delete the columns you don't need rather than hiding them.

Hiding is great for a temporary view, but if you're trying to paste new data into an XLSX, hidden columns are basically "invisible walls" that lead to alignment mistakes. If you delete them, your Ctrl + V will always land exactly where you expect.