XnView Software

Is there a way for an image to appear in folder that allows me to navigate only in xnview, for example drag and drop image from web browser into xnview thumbnails as it is in browser, whether .jpg or .png (usually) and NOT as .bmp? The way I do it now is drag and drop from browser to Windows ...

I can tag a png file using xnviewmp by writing into the iptc caption field, and the thumbnail shows and "xmp" tag in the browser, but when I refer to the metadata, nothing appears in the iptc caption field -- it is blank -- what am I doing wrong?