My Crystal report version is 5.1

I need to format a fiel number and it is a telephone number. What is the correct formula or function to format this field in my version.

The data fiels belong to a table from msaccess or mdb

actually the number is printed like this 2136407658
I need in my report to print like this (213) 640-7658

Someone gave me this example but this is not working

Picture("2136407658","(XXX) XXX-XXXX")

I have not this picture fuction in my Crystal report Program, I have only number group Fucntion.