How to configure DD-WRT PPTP client without default route?

Question

Network administration

It is necessary to raise the tunnel to the office network via PPTP.
The PPTP client from the Services->VPN tab, which was actually intended for this task, could not be started on any piece of iron. I don't understand how it's supposed to work at all. The scripts found on the Internet for this case did not give anything. If anyone managed to get it to work, I will be grateful for the hint.
The second option is to use a PPTP connection for the WAN interface. Everything is up and running here. But it is not possible to force dd-wrt not to register this connection as a default route.
Alternatively, I can prescribe the necessary routes after connecting, but again, I did not find where to hang the script.