very newbie question (sring confusion)

[Lloyd Dupont]

maybe it's late, or I have a hard time reading the string and array class 
methods.. (which I have! :~)
anyway, I have a very simple problem and it seems hard to fix!

let say I have a list of resource named preferential order (favored first) 
and I'd like to do return a list of match in preferential order (with always 
the default last)


for example:
my resources (default first): "en-AU", "fr-FR", "fr-BE"
my matches: for xxxx i'd like to return a variable list / array xxx
"en-US" => "en-AU"
"fr-CA"  => "fr-FR", "en-AU"
"fr-BE"  => "fr-BE", "en-AU"
"es-EP" => "en-AU"

how could I do that?