refer this link http://blogs.mathworks.com/simulink/2008/12/25/initializing-parameters/

You can do it in two ways:

1. Run the script file and save the variable values in the workspace. (When you run a script file the values of the variables are stored automatically in workspace). Then, in the Simulink model, write the name of the variable in the window where you want the numerical values of the variable. Run the model, it will take the numerical value of the variable defined.

2. In the script file, after writing the code and taking all values, call the Simulink model by using "sim" command. Running this script, the model will run with the values defined by the user in the script. (Please ensure that before calling the model in the script file, write the name of the values of the parameters in the model in place of its numerical values).

Regards

T.Prakash

in additions to the Tapans answer, you can use "To Workspace" block form sim library to save your output variable to the MATLAB work space directly. After simulation you can access those output variables from script file.

Regards

Vikrant Singh Thakur

Clearly, this can be done in many ways, as can be concluded from the above answers. But the best method would be copying(and modifying if necessary) the contents of the script into a "function block" directly in Simulink, you can specify as much inputs and outputs as desired, it's simple and the performance will be much  faster. If the script needs to be run only once to act as a constant throughout the simulation, use global variables.

Another case of doing this, especially if you need the output of the script to a certain block parameter is to use set_param('model/block', parameter, value) in your scripts and then run the Simulink model.