If you create a droplet in Photoshop, you can run this at the time of export from Lightroom in the post processing options.
You can put any item in the Export Actions folder that can be opened with a set of photo files. For example, you can place an executable file or shortcut (Windows), or application or alias (Mac OS). Items added to the folder are listed in the After Export menu of the Export dialog box the next time you export photos.
You can also add Photoshop droplets or script files to the Export Actions folder.
1. Do any of the following to open the Export Actions folder:
*
In the Export dialog box, choose Go To Export Actions Folder Now from the After Export menu.
*
(Windows XP) Navigate to \Documents And Settings\ [username] \Application Data\Adobe\Lightroom\Export Actions\.
*
(Windows Vista) Navigate to \Users\ [username] \App Data\Roaming\Adobe\Lightroom\Export Actions\.
*
(Mac OS) Navigate to / [user home] /Library/Application Support/Adobe/Lightroom/Export Actions/.
2. Add the item to the Export Actions folder.