MATLAB TO STEP 7 MICROWIN

I need to write a certain value from Matlab to trigger action in the ladder program which i wrote in STEP 7 MICROWIN through MATRIKON OPC FOR SIEMENS PLC SERVER(or any other software which you will recommend me to use),The ladder program is just simple,one input(I0.0) and one output(q0.0),so i need to write a value from MATLAB to the input I0.0 to trigger the output Q0.0 in the Microwin ladder program