Adding horizontal pixels on video

Hi ..

i got 60-70 clips with diferent aspect ratio..

the point is for example, if video is 960x720

i want to add extra pixel below video so aspect ratio will be lets say 960x750, but this 30px will be black and below video

I need most easy way to do this ..

you have to have in mind that all clips have different ratio .. so it is not option to    

define ratio ..

I'm using "New item" to define aspect ratio of clip/creating sequence..

i know for example to see ratio and    

define creating sequence on begining  .. then insert clip and move X,y .. but I'm trying to avoid that.... to much work

so any suggestions