Whenever we do not find an option to do a specific task we may find a command line tool more promising.
To achieve a video with clipped content from a time segment of our source we basically need the video filters trim, and crop from avconv/ffmpeg (whichever you prefer to use). Please read the documentation in the libav manual sections for all options.
Below example will produce a video from the first minute of our source with cropping a central area of 1024x768.
avconv -i <inputfile> -vf trim 0:60 crop=out_w=1024:out_h=768 <outputfile>
Cropping from another position than the center will need different parameters which can very nicely be fine-tuned (several examples are given in the libav documentatiton). Audio is not treated in this example. If your video contains audio you may have to trim the audio track as well.
The resulting clip will then have to be of course joined again with the orginal video which we will also have to trimm to the beginning, and the end of our transformed clip.
The crop feature is hidden in the clip's properties/layout settings. After we had selected an area (use the Razorblade too) of our clip we may select this sub-clip's properties with a right mouse click.
In the now opening menu choose the Layout tab to select an area to clip. Adjust height, width, and X, Y values until you are happy. A preview window will help doing so.
Below example uses a video with a constant view on the scene (as it is shown in the lower screen shot).
Enlarged to 200 % at the start of the clip
Back to 100 % at the end of the clip
In the example above I started with a clipped region of the video at the beginning of my sample video fragment zoomed to 200% ("Start of Clip"). By undoing the enlagement at the end of my fragment to 100 % ("End of Clip") OpenShot will render a smooth transition between the two extremes (200% -> 100%) very much as if we had operated the camera zoom. With values for X or Y we can do the same resluting in an camera shift movement from the beginning to the end of the clip.
In case we want a static clipped area only we just make the effect's value the same for the beginning and the end of the clip.
Details: OpenShot Manual