Getting <alt text> data from an xml file into Photoshop's File Info/Alt Text field

I have an xml file that contains the metadata <alt text> =. Is there any way to automate getting that data into Photoshop's File Info/Alt Text field? I'm not a programmer so the best I could come up with was extracting the xml info using GREP, then using an Automator action to loop cutting selections to the clipboard. I then made an Action in Photoshop that goes to the File Info window, but then I have to manually scroll down to the Alt Text field and paste it in. I have hundreds of photos and this is getting a little old! Any way to automate it further? Thanks!!