Scripting in Photoshop didn't happen until Photoshop CS. Other than getting into programing language, I doubt there is much you can do.
Actually, there was scripting available in PS7 but there wasn't any ScriptUI until the next rev, PS 8 (aka PSCS). There were a lot of other things that were missing, too, but people were still writing code for PS7.
As for inserting EXIF Date/Time onto an image, several people have written code to do this, I just don't have any links handy.
You can use an action the use a script to add a text layer containing EXIF Information. The Action could then position the layer over the image using Photoshop align layers to selection and also style the layer like set the fill to 0 and add effects like drop shadow and and emboss to make it transparent. You could modify a script like this one. It would be easy the format the text layer for the content you want. on the image.
Before proceeding further, it is to be highlighted that the version being referred to is Photoshop CS5 Extended which is actually Photoshop Version 12.1 and is a part of Adobe Master Collection CS5.5. A screenshot of the version information is attached below for information.
Hence, I dont understand the concern expressed by many about the lowest version eligible for scripting being available in the product.
My version is in effect 12.1 and not 7 or 8.
Accordingly someone may advise on what script to use for inserting the EXIF data onto the image. I also want that the positioning of the text is predetermined and same for a batch of images required to be processed. I dont want to fix the position of text for each individual image.
Did you read my append and xbytor2 append. There are many Scripts that add some EXIF date to images. Most do it by adding a text layer. An action could use such an script to add the text layer then position and style the text layer. If you have many different size and resolution images files you need a script that will set a good font size for the image being processed. Such an action can be batched. You can search the web for these script or modify the one I posted for you.
A Photoshop script can even your default web browser on google maps for the image's location if there GPS info is in the images EXIF.
Getting old and small type. Looked like ps 5.5. No problem scripting to get EXIF info into photos.