echo pre_[aa,01:03,bb]_[x,y]_post | ./xstr.pl
pre_aa_x_post
pre_aa_y_post
pre_01_x_post
pre_01_y_post
pre_02_x_post
pre_02_y_post
pre_03_x_post
pre_03_y_post
pre_bb_x_post
pre_bb_y_post