Sorry, at work Youtube videos are blocked by firewall, so I can't see it.
Anyway, issue _MAPWSPACE and turn it on, then in Display Manager => NEW => LAYER
This applies to my glorious Map2006, so in your version it might be different.
what exactly do you mean by join?
i placed A-21, A-22, C-21 as texts in autocad. i just linked them by loading the excel using mapattachdb, double clicked the sheet, defined the link template, clicked the link records and selected the objects. is that it??
No way, lady.
As suspected, your spreadsheet does NOT contain the A-21, A-22, C-21 values, so you cannot link automatically Acad objects to Excel records.
In XXI century, we don't join them manually one-by-one, so please feed your .XLS table with those values.
When you're done, issue the _ADEGENLINK command, and choose the "Enclosed text" linkage type.