Access Appengine from external server using VPN no internet

[Pablo Lopez]

Hi, 

I'm not much of a networking guy, mainly a programer and I have this issue that I need help.

 We have an appengine flexible project using a vpn and vpc  to access some company servers that are private in the company network (no internet access). But now I have a requirement to create a service on my project that is visible to the same savers on the company network through the vpn. 

I can ping the appengine instance using its private ip address (I got it doing ssh to the instance), but every time the instance changes it gets a new ip so I can't keep track. So is there a way a can set up a static internal ip or a dns so I can access an app engine service I'm building from the company servers. 

Cheers