DrAC,
We do use Excel spreadsheets regularly and they work well.
Try these steps (which are pretty much the same as for any imported item) and let us know if you have any problems:
Open the patients chart to imported items
Click "import new...files" (or hit ctrl-f)
Browse for items
Navigate to the name of the Excel sheet you want to use (can be a blank sheet, or a template you created).
Click open. Select a category and name.
Click import item.
You should see an Excel icon in the list of II on the left.
Here is where the fun begins. If things go properly, when you click on the icon, the spreadsheet will open in the pane at the right. If it does not, then you need to begin to tinker.
If you have a problem, the issue is often dependent upon the operating system of your machine, your default browser (believe it or not), and the default program used to spreadsheet files.
Give it a shot and let us know how it goes.