Apple

on searchDirectory:folderPOSIXPath forExtensions:extensionList

-- make NSString of folder path

set folderPathNSString to current application's NSString's stringWithString:folderPOSIXPath

-- get file manager

set fileManager to current application's NSFileManager's defaultManager()

-- ask file manager for all subpaths recursively

set theFileNSArray to fileManager's subpathsOfDirectoryAtPath:folderPOSIXPath |error|:(missing value)

-- filter the array according to extension

set theFileList to (theFileNSArray's pathsMatchingExtensions:extensionList) as list

-- combine subpaths and folder path to get full paths

set finalList to {}

repeat with aSubpath in theFileList

set end of finalList to (folderPathNSString's stringByAppendingPathComponent:aSubpath) as text

end repeat

return finalList

end searchDirectory:forExtensions:

set folderPOSIXPath to POSIX path of (path to desktop)

tell script "<lib name>" to set thePaths to its searchDirectory:folderPOSIXPath forExtensions:{"asobjcex3doc"}

References:
	>Re: file list as data (From: "Jan E. Schotsman" <email@hidden>)
	>Re: file list as data (From: Bruce Robertson <email@hidden>)
	>Re: file list as data (From: Christopher Stone <email@hidden>)