[LAU] how to edit MIDI by applying selection rules?

Hi, Some days ago I was working on a MIDI project that required selecting a large group of notes and transposing them. The notes to be selected were short notes alternating with long ones. Using Rosegarden the only way of doing it was to shift-click (in piano roll) on the short notes which became impossible since sometimes clicking on the short note would also select the long one next to it. Also if I made a mistake I had to start over again since in Rosegarden (ver. 1.5.1 at least) you can't unselect a note from a group of already selected notes. Even if it was possible to shift-click on each note without problems it would require a lot of time. So, my question is: are there any open source MIDI editing tools that would allow me to do something like this quickly? This kind of tasks are easy to accomplish in other proprietary softwares using filtered selection by creating your own set of selection rules and applying it to a MIDI region or track (like: select all notes between such and such duration). Is there anything like this for Linux? Any command line MIDI editing tools already around? In other cases it would be nice to edit groups of notes selected by pitch or velocity. Thanks! Hector