Hi Amir.
Thanks for your question.
I believe I understand what you’re asking for, but we’re limited in helping with customizations, per our Scope of Support / Terms. However, I can try to help point you in the right direction.
The only output from our calendar is in iCal format, which would then need to be interpreted/parsed by Google Calendar’s iCal reader. In order for our calendar’s Additional Fields to tell Google Calendar to do something special with that information, you’d either need to customize the iCal export’s data (a customization) or you’d need to otherwise change it (a customization) in order for Google’s iCal parser to do the desired action (e.g. import at some custom datetime).
If you need some coding help, you may want to ask your developer or reference our list of known customizers.
I hope this information was at least helpful to you conceptually.
Please let me know if you think I can be of further assistance.