Need help understanding shape/shaperange AlternativeText

[Team]

How can I find out the file extension of an image inserted on a slide in a
PowerPoint presentation?

I have created a tool to find out the image file extension, inserted on a
slide. I use the following code for this.

"ActivePresentation.Slides(1).Shapes(3).AlternativeText".

In PowerPoint 2007 it returns the file name with extension, but in
powerpoint 2003 it returns only the file name(without extension). Is there
any way to find out the image name extension inserted on a slide?

 

[Team]

Thanks a lot for your last replay.After my research I came to the conclusion
given below.

A presentation with inserted images, which is created by using PowerPoint
2003, shows blank value for the AlternativeText property(for inserted
images) in PowerPoint 2003. If we opened the same presentation in PowerPoint
2007 it shows Image file Name but without extension for the AlternativeText
property.
But, a presentation with inserted images , which is created by using
PowerPoint 2007, contains value for the AlternativeText property (for
inserted images) with file extension in both PowerPoint 2003 or in 2007.

My aim is to get the format(bmp,jpg,gif,etc) of inserted image in to a
PowerPoint presentation,How can I get it.