With the command "-insert" (command line), can I introduce the name of my block without the extension "dwg"

Hello every body

If I use the command "-insert" (in the command windows), I can't insert my block when I tape the name without the extension "dwg".

I must put the name with the dwg extension (for every blocks) and it's not easy when there are a lot of blocks to insert.

Is there a setting to allow to use the block's name without the extension ?

Very thanks for your answer

bruno