In the External References palette, select the reference name that you want to bind.
Right-click, and click Bind.
In the Bind Xrefs dialog box, select one of the following options:
Bind converts the objects in the xref into a block reference. Named object definitions are added to the current drawing with a prefix of blockname $n$, where n is a number starting at 0.
Insert also converts the objects in the xref into a block reference. Named object definitions are merged into the current drawing without adding prefixes.