First of all it's LOADS easier to just call your own file AIRSTRIK.AUD then.
Secondly, airstrike isn't in the normal game list. And changing its filename and/or replacing its AUD file will not magically make it appear in the list either.
As far as I know, my C&C95 UGE beta 3.0 is the only tool that is able to edit the settings of the tracks in C&C95.
http://nyerguds.arsaneus-design.com/tools/cnc95uge_beta.zip