Not really possible to do, nadox - macros can't make decisions based on the range of targets.
However, this will use judgement on focus, and if you hold down ALT while you hit the macro, will cast crusader strike on your focus. If your focus is not hostile (or is dead, or you don't have a focus), it will instead cast Crusader Strike on your target if you hold ALT, or just cast Judgement on your target. If you want it to be used on the target of your focus (ie, if you focus the tank, and want to judge whatever the tank is targetting), just change "@focus" to "@focustarget".
Code:
#showtooltip
/cast [mod:alt,@focus,harm,nodead][mod:alt]Crusader Strike;[@focus,harm,nodead][]Judgement
Or, in other words:
If ALT is pressed:
Focus Exists, is not Friendly, is not Dead? Cast Crusader Strike on Focus.
Focus does not Exist or is Friendly or is Dead? Cast Crusader Strike on Target
If ALT is NOT pressed:
Focus Exists, is not Friendly, is not Dead? Cast Judgement on Focus.
Focus does not Exist or is Friendly or is Dead? Cast Judgement on Target.