I guess you're doing something like
http://www.kinook.com/Forum/showthre...?threadid=4076
but using $(ConfigurationName) rather than $(OutDir)? Those types of macros/variables are resolved by Visual Studio, not by VBP. They will not be replaced by an actual configuration name in the project file, but will instead be interpreted and converted by VS when building the project.
When using an expression like that in the replacement field of the Replace in File action, you need to escape the parentheses (see the attachment in the link above):
$\(ConfigurationName\)