How can I solve this Error #4001 realted to user-defined C-code in Simulink/s​tateflow?(​using Matlab R2007b, Targetlink 3.1)

I'm using a user-defined C code in Simulink/Stateflow. I followed the instructions shown in the Targetlink demo under stateflow: SF_USER_FUNCTIONS.

1. I created dummy header and C functions as suggested in the demo and included them in Simulation target.

2. I used a add file block from Targetlink library, where I inserted the actual .C file(not the dummy one) This is the error message:

Error #4001: Cannot find implementation of user-written Stateflow function CntrUpdate Check if the script "sf_cntrupdate_script.m" exists on the MATLAB search path.