Reduce the number of commands

Hello!

I want to:
1. Resize the images (as an example max 300x300)
2. Remove imageinformation
3. Give the images rounded corners
4. Add the image with rounded corners on a transparent square image 
(300x300)

Programming sequence below performs this but with 3 pcs of commands
Is it possible to simplify in some way?

(Code for Windows / DOS)
convert -define jpeg:size=300x300 c:\temp\pic\hatching_orig.jpg 
-thumbnail "300x300>" c:\temp\pic\pad_extent.png
convert c:\temp\pic\pad_extent.png ( +clone  -threshold -1 -draw "fill 
black polygon 0,0 0,25 25,0 fill white circle 25,25 25,0" ( +clone -flip 
) -compose Multiply -composite ( +clone -flop ) -compose Multiply 
-composite ) +matte -compose CopyOpacity -composite  
c:\temp\pic\rounded_corners.png
convert c:\temp\pic\rounded_corners.png  -background transparent 
-gravity center -extent 300x300 c:\temp\pic\Image1.gif


//Jan