One Texture2D from multiple others

Hi guys!, I've been struggling to find a proper way to create a new Texture2D based on multiple others. The Idea is that I dynamically load up a list of Textures2D form a certain folder (that's done). so I have this list of textures. What I want to do is to create a new Texture that has every texture on the list in such a way that it has 1 column and X rows where X is the count of the list. That way I'll end up having one texture with every texture of the list in 1 column and I can use this to create a particles system. So the problem is generating this master texture. Can anybody help me do this?. Thanks!