External Subroutine / file

Hi... I have created an LED matrix and programmed a number of different display patterns. I have also purchased a data logging shield from adafruit in hopes that it can be used for something other than data logging.

Is it possible to define each display pattern as an external file on an SD card and have the file contents formatted syntatically as an arduino subroutine.

In my main arduino program, I want to use a push button routine that reads a specific file on the SD card, parses the contents and then have the main routine run the code?

This would allow me to more dynamically interchange patterns without having to recompile the main program.

Is it possible to define each display pattern as an external file on an SD card and have the file contents formatted syntatically as an arduino subroutine.

No, but...

It would be possible to create a command language that the Arduino would interpret. Then, each pattern would be a series of commands (and data) in that language that would be read from the appropriate file on the card.