You say: "they told me that has the same internal network."
It does not matter what hardware the other end is, but you cannot have communication over a normal VPN when you have the same network on both sides.
First point is to make sure you have a different network defined on each side of the VPN, either by changing the IP range on one side or by using source NAT on both ends.
When it is a different network, but just a chunk out of the range used at one end, ie local network is a 10.200/16 network and the other side is 10.200.200/24 you could use a exclusion group on the Check Point side.
So there are a lot of possible answers here.
Regards, Maarten