can't display link as icon
 

I have a list of items in one column and want to link to the description of
each in the next column. Excel displays the lengthy description in the link
cell, and I just want a space-saving icon so the user can display all the
detail only if desired. The instruction in Help sound exactly like what I
want, and say:

"You can display a linked object or embedded object in a workbook exactly as
it appears in the source program or as an icon. If the workbook will be
viewed online, and you don't intend to print the workbook, you can display
the object as an icon. This minimizes the amount of display space it
occupies. Viewers who want to display the information can double-click the
icon.
1. Click the icon for the linked or embedded object you want to display.
2. On the Edit menu, point to object type Object (for example, Document
Object), and then click Convert.
3. To display the content of the object, clear the Display as icon check
box.
To display an icon of the object, select the Display as icon check box. To
change the default icon image or label, click Change Icon, and click the icon
you want from the Icon list, or type a label in the Caption box.
"

BUT I can't even do step 1 because there is no icon to begin with. When I
open the edit menu from the cell, the "Link" and "Object" options are both
greyed out.
Any ideas how to make this work?

many thanks.