I have an RDLC file in which I want to make an expression.
Here is the image of properties of expression. I need to concatenate First Name, Last name and Middle Init.

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
The following examples works for me:
or
Have a look at MSDN