How to extract data from text files(I've got 1000 text file) and save separately group by group in matrix.

Hello,for everyone who wants to help me.My problem is that i do not know how to extract data from text file row by row,which meets my criteria.Inside of text file i have got (X,Y) coordinates and deformation distance at Z-axis.I have to extract the deformation distance data at Z-axis which meets criteria(for example: x=15,y=25 according to this numbers i need to extract the deformation dist. at Z-axis and save it in matrix.And this step will be applied to all text files,and all Z data must be saved in one matrix.)