How change variable during HIL simulation ?

I need to change the value of the tunable variables during HIL simulation without using Matlab.

I have added the external mode, so I tried to use it the same way that it can change variables in the external mode. For this purpose, I tried using the function:

'void PUBLIC SetParam (RTWExtModeInfo * i, const char * pBuf)'

which is in the file 'ext_svr.c' that reads the received TCP packet and set the params.

I don't know how I can simulate that package. Or any form to set params during simulation without stop it.

Any help? ;)

Thanks in advance