plist bundle version values
Yes, you can use ${VARIABLE} style macros the Info.plist file.
We make a user-defined setting in the project called APP_VERSION, and then use ${APP_VERSION} in the CFBundleGetInfoString (Get Info string), CFBundleShortVersionString (Bundle versions string, short) and CFBundleVersion (Bundle version) keys. At build time, the variable gets filled in with the correct version.
Watch out though because sometimes a clean build is necessary for Xcode to update the Info.plist file as it does not do dependency checking against the variables.