Good news everyone
I thought it was not possible ...but after some digging - YES WE CAN !
I've managed to implement manual teleportation in serious sam on demand
there is a BUT of coz ... - it will only works for users who has Fix42 mod ... (new version coming up)
First test of it looks promising :
teleported to (1000,1000,1000) coordinate...
users who do not have Fix42 mod - will get de-sync ...so there'll be some restrictions.
Anyway - it works !!!