If you have IS Boxer or HKN, you can set it so:

Press 1 of key 'A' = Outputs the keybind for Macro 1.
Press 2 of key 'A' = Outputs the keybind for Macro 2.

If you're using something else, put them on two nearby keybinds.
1 and 2, for example.
And just alternate which key you push.