Halp.

i may be out of touch but my perception of A5-A9o is that they play like shit when we don't have the initiative, even in position. i can't be bothered typing out what my exact calling range would be but it would probably involve 22-TT or JJ (though i may fold the lower pairs if we have chronic 3bettors in the blinds) most suited aces, most suited broadways, KJo+,65s-T9s, a few of the higher suited one-gappers and maybe some more suited two-gappers if i feel like i have a significant postflop edge.

again, i could be way off

edit: the above would be a typical calling range for me vs a reg. you provided no info on the player in the CO so i just went with that. if he's a 66/60 maniac who has been open-shoving every flop, that's a different story