Currently, I would select a bunch of polylines in a fgdb, using Selection > Selection by Location. I will then be using a "AOI" (Area of Interest) polygon to help me select the polylines in a fgdb that are within AOI (usually, i will choose "are completely within" option), and these selected polylines will appear on one of my mxds.
I would like to have a script that can help me do this: running the selection of polylines using AOI polygon as a reference. So, whenever i open up that mxd, i will be able to see the updated polylines on it.
FYI, the feature class in fgdb will be updated monthly (names of fgdb and its dataset remain unchanged), and there might be a increase or decrease in the number of polylines every month (there are to be captured as long as there are within the AOI.