C# directory path name contains invalid character

In a C# 2008 application, I want this program to point to a executable that it needs to run called 'client.exe' as indicated by the app.config file value I listed below. My problem is the part of the directory path called 'co1 & co2' has an illegal charcter in it which is the '&' part. The production location has this name in it.

Thus can you tell me how to change the '&' part of 'co1 & co2' so that the & will be a valid part of the directory path?

Here is the app.config file I am referring to: