Hi
If you're importing selections from text file, put this as the last line of the text file:
#all_active#
this will keep all other selections active for triggers etc.
make sure your conditions are appropriate if you do this, and please test in test mode.
Also just as an optional suggestion, rather than importing selections, you could keep your selection names in a text file and use these conditions in your trigger in this order:
selections rank is the maximum
and selections name is in file <path to text file>
this will find the highest ranked selection in the market, and then check the selection name is in the file.