Excel replace cell value based on a value in another column

I am wondering if there is a way to replace a cell value from another list, without having to write a VB script.

Here is the problem I am trying to resolve:

I have image URLs in a column:

img1.jpg

img400.jpg

image100.jpg

and I have another column with many image URLs in a single cell, separated with comma e.g.

img32.jpg, img120.jpg, img1.jpg, img43.jpg, img56.jpg

img400.jpg, img495.jpg, img402.jpg

image407.jpg, img608.jpg, img100.jpg

I would like to replace img1.jpg with:

img1.jpg, img120.jpg, img32.jpg, img43.jpg, img56.jpg

and img400.jpg with:

img400.jpg, img495.jpg, img402.jpg etc.

The list is huge, with more then 8000 rows in it.