Let me clarify Chip's response.

How to display the worksheet of an .XLA that contains data.

You don't. XLA's are hidden and you cannot (or should not not) display
anything from the XLA.

You never ever want to expose the sheets of the add-in to the user (i.e., at
run time).

If you need to manipulate the data (at design time), select the ThisWorkbook
object under the add-in's VB Project, and in the Properties pane, change
IsAddIn to False. This makes the workbook visible, so you can manipulate it.
Change IsAddIn back to True when finished.

In general it is a more robust, more flexible, easier to maintain approach
to keep the data sheet in a workbook separate from the add-in.

- Jon
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Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
Peltier Technical Services, Inc. - http://PeltierTech.com
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