[Gretl-users] Vintage Data and fcast command

Hi, I need to run fcast command on Vintage Data. I explain myself. For the dependent variable, every month there is a new observation and the previous last is changed by revision. So i need to run a recursive prevision using fcast command, but every time gretl make an estimate ex 01:1991-02:1991-03:1991 the dataset is changing. Where i can find the fcast command code? Maybe i can try to change it. Is there some extension for this? Someone can help me to do this? Thank you