Combining 2 png in one with convert

I am using convert from ImageMagick to combine 2 png in one using this script :

convert background.png logo.png -layers merge final_background.png

It is working but I would like to move the logo at 20 pixels from the top, is 开发者_StackOverflowit possible ?

Thanks a lot

Thierry

I found how to do this :

convert background.png -page +0+130 stationLogo.png -page +0+440 -layers merge Default.png