Hover over cell displays data from two cells on a different sheet

Since no one has posted, I'll say this:
It is possible, but it is very hard to create and to maintain. It would require a special handling of each cell and some VBA. The technique is more of a hack than a method Microsoft tried to make accessible to users.

Okay, when I saw 'Newbie' I thought it was a newbie to Excel not this forum. Here is an example file. I used conditional formatting for the red, but it could also be put in the macro. For your issue, you would use the same HYPERTEXT and macro technique, except the 'Friendly Text' attribute would be the value in the cell you want to display - probably use a separate column with the HYPERTEXT referencing your current values.
The VBA would need to be passed an identifier on which cell you are hovering over - maybe ROW() and COLUMN()? With that info, grab the data from the other sheet and put it in a text box which is displayed while they hover.
Some pointers:
- Apparently you can't use a comment for this to work. The comment 'interferes' with the macro call, so you lose your hover detection.
- You probably need to 'ring' your data with the same HYPERLINK trick, so that your macro is called to remove the text box when the user is no longer in your desired 'hot zone'. Otherwise, the text box will stay there until they hover over another hot cell. I used this technique to erase the text - the red cells (when hovering) are my ring.
- The response time is a little slow. So, if the user moves their mouse quickly, the macro may not fire. Worst case is that the text box stays visible.

Thanks for the rep bump for telling you something was tricky. Hopefully this example file is worth that 'point'.

I just looked at your link. Let me say that the technique in that link would work if your data does not change. I assumed the data in the separate sheet is modifiable, hence the need for a macro to be fired when you hover. If your data is static, then you can use the weblink's macros to generate a bunch of comments with the data you want.
When you say:

but it tries to add the data and my data is text

that is okay. In fact, the comment wants text, and his first example has text in it

He does show a method with Worksheet_Change, and that is an alternative solution. I try to avoid using that type of approach since the macro is called for EVERY worksheet change and it can mess up your UNDO if you are not careful. But, it may be a better and easier to maintain solution than what I provided.