[PLUG] question on filling in GUI popup windows

[logical american]

Just recently, a company that I work with changed their pop-gui login 
window which has fields which have to be manually answered.

I need some linux program which will know how to answer the name box 
inside the gui frame, then jump down to the password, and decrypt the 
prestored password, and put it into the password box  (we are running 
ssh, so I don't expect that the password will be visible in the data 
stream)  I do NOT want a password stored in the clear.

Is there any linux program which can handle this efficiently?  Expect 
only seems to handle CLI input, not a gui frame.

The company code uses java, but I don't know what they are using for the 
gui creation.

Thanks for some insight on how to handle gui logins.