How to exclude one category with Shortcode

I use a shortcode so get the last 3 posts but exclude the most recent with offset. It work correctly.

Now I wish to exclude one specific category but is not clear to me how to do this.

I tried several way but without succes.

Shortcode I’m using is:

[rpwe limit=”3″ offset=”1″]

I tried adding on the shortcode (i want to exclude category with ID “2”)

[rpwe limit=”3″ offset=”1″ cat=”1″ cat=”3″ cat=”4″]
or
[rpwe limit=”3″ offset=”1″ cat=”1,3,4″]

Not works.

Is there any way event adding some come on the function.php of the plugin?

Thanks