Can I populate a text field in one PDF with the modification date of a different file ?

Question

Rather convoluted problem here but I'm trying to place a text field on a PDF document that serves as the main menu page for a library of interlinked PDF documents
The complete library contains over 7,000 files and additions are added and documents changed almost daily.
We currently use batch files to open the main menu from it's shortcut and this runs a check on a sync log file (.txt) to ascertain when the last time the user synchronised with the server to get the latest copy of the files.
Between a certain time range they are told how long it has been since they sync'ed and are offered the option to sync before opening, after a prescribed timeframe they cannot enter without synchronising. We use Allways Sync to conduct the file synchronisation with our mother files on our server.
What I'd like to do is take advantage of Allways Syncs automatic synchronisation options to synchronise on log on and at prescribed idle periods there after.
This works fine but I'd like the text field on the main menu PDF to say when the last synchronisation took place - easy if the main menu is the last file modified .. just use info.modDate.
However, the main menu is rarely modified therefore I wish to import the text to populate the text field from a different file.. either by interrogating the other files modifictaion data (though I doubt Acrobat can do this) or by simply importing some text stored in another file (a .txt file?) which has previously been created by batch file commands.
Any assistance would be greatly appreciated.
Regards,
Nifty Styles
(Norfolk, England)
P.S.  I'm using Acrobat 8.3.1. Professional on Windows XP (SP3).

Answer 1

Thank you for all your help above.
Just to confirm your advice, am I right with the following conclusions? :
1. The script (function) to fill the text field with the modification date of a different PDF file needs to be stored in a folder level .js file.
2. The document containing the text field needs to call the .js function either within the document script or within the custom script property of the text field itself.
Further to that can you just advise on the syntax for accessing the modification date of the other document.
Do I need to assign a variable to the address of the file to be used, and then use this variable in the text form filling script (as below) or can I use a direct file reference at the .modDate command.
var LastSync = "C:\sync\bin\lastsync.pdf";
var strMsg = util.printd("h:MM tt",LastSync.modDate) + " on ";
strMsg += util.printd("dddd, d mmmm, yyyy",LastSync.modDate);
this.getField("LastSyncDate").value = strMsg;
If the syntax is totally different to the above I would be very grateful for some guidance in the right direction.
I much appreciate your time to help me ... I'm almost there.
Kind Regards,
Nifty