you could use the following code to get the path to the winamp skins folder using the registry,
function GetWinampSkinsDir: String;
Reg := TRegistry.Create;
if Reg.OpenKey('\Software\Winamp', false) then
Result := Reg.ReadString('') + '\Skins';
ShowMessage('Unable to locate winamp!');
still working on the Current Skin but i'll let you know when i come up with something.