Q:

Insert image file to publisher document in place of existing image

I have publisher document used as template. 

How to insert image from file in place of "?"  image. 
Probably it's same way as for MS Word but I can't find out. 
I access that template this way:
using Publisher = Microsoft. Office. Interop. Publisher;

Publisher._Application pubApp = new Publisher. Application();
Publisher. Document doc = pubApp. Open(docPath);
Publisher. Page templateCard = doc. Pages[1];

A:

Basically:
shape. PictureFormat. Replace(filePath);

Best way to find my template image I figured out is set alternative text to my image and just chack it:
foreach (Publisher. Shape shape in currenPage. Shapes) {
    if (shape. AlternativeText == "DICKBUTT")
        //here you do your stuff
}

