in simulinke model there is a "to workspace " assume its var is "sout" that i want this var "sout" identified by my gui program
Simulink data from To Workspace block is always saved in Matlab base workspace. So your variable "sout" will appear in matlab base workspace after the simulation.
You can access this variable in you GUI program (or in any other) function using
data = evalin('base','sout');
Using this, values in "sout" from base workspace will be copied in variable "data".