How to sort search results from SCOPUS or Web of Knowledge by number of citation in a specific field? I use SCOPUS or Web of Knowledge to search papers. 
What I need to do is to sort the result in a descending order of number of citations.
SCOPUS and W_of_K both provide this feature.

But I further need to confine those citations only in a specific field.
For example, statistics paper can be cited in another statistics paper or in a medicine paper. What I'm interested in is how many times this paper is cited in another statistics paper.

Using scopus and Web of science, I can see all the papers that cited this paper and then confine to a specific field. But I have to do this for all papers one by one.
Thus I wonder if there is any search engine that can to this automatically.
There is no automatic solution to this - it is an extremely time-consuming labour, sometimes performed by bibliometricians - and often only by those with access to full editions of either database (not the web-interfaces, with strict limitations to download sizes).

It is also a tricky subject, as the defionition of e.g. a statistics paper may differ from what you are actually looking at: journal categories. Papers on any topic are also published in journals not directly related hereto, there are plenty of translational and multi-disciplinary journals as well - in other words, what may appear to be a trivial task is actually very complex.