Not sure exactly what you mean by embed, but I'll give it a shot.
If what you want is the form to open when the workbook is opened, it's pretty easy.
In the VB editor, double-click This Workbook from the project pane. Type the following:
Private Sub Workbook_Open
UserForm1.Show
End Sub
This will open the userform whenever the worksheet is opened. Check the Excel help files for Event Procedures (since that is what you are using) for more details.
If this is not what you meant, please clarify and I'll try again...
K