If you have a created a template with annotation scales using the SCALELISTEDIT command and want to add them to an existing drawing here is what you can do to save some manual work.
The scale list is stored separately in each drawing in AutoCAD 2008 and forward. In older versions they where saved in the AutoCAD profile.
(command "insert" "*c:\\your\\path\\template" "0,0" "" "")
What happens here with this line of AutoLISP code is that the block/drawing template is inserted into the current drawing and exploded, the block definition is not added but the annotation scales are added. Make sure to change c:\\your\\path\\template to the location and the name of your template. It can be either a DWG or a DWT file. Then if you have several existing drawing you can use a batch script application like SmartPurger or ScriptPro. If you want the scales added to all your drawings that you open you can create or edit the acaddoc.lsp file.
If you want quick and easy access you can for example make a toolbar button macro or tool palette tool and on the Command string adding:
^c^c(command "insert" "*c:\\your\\path\\template" "0,0" "" "")