Yes, its very much possible.
There is a naming convention in CA DevTest for Virtual services.
To create a VS using RR pair your request name should end with "-req" and response as "-rsp" .For example, request can be named as "request-req.xml" and response as "response-rsp.xml".
If you wish to have multiple responses for a single request then response names should end with "-rsp", "-rsp2","-rsp3" etc.For example a request can be named as "request-req.xml" and responses as "response-rsp.xml", "response-rsp2.xml", "response-rsp3.xml" and so on.
I hope this helps you.
Thanks,
Viraj