Replace engine from another company?

Yes, you can swap in engines from other brands - even a 6-cylinder, BUT it is absolutely not a bolt-in job and requires major custom fabrication.

For 99% of owners, the realistic swaps stay within the Mazda / Ford family.

You can make almost anything fit, it will just take work. What engine were you thinking?

As Ken said, Yes it's possible, however there is a lot of work involved. The first being, are you planning on this being a street legal car. If not then pretty much anything can be done. However if you want it to be street legal and insurable it gets much harder very rapidly. As an example - I decide I want to put a modern LS engine in a 72 Oldsmobile. State says I can BUT ALL of the emissions equipment must be installed with it, It also has to have a fully operational OBD port and meet the standards of the engine year. However you are thinking of swapping into an all wheel drive, that means you not only need to fit the engine under the hood you need it to fit into the chassis and be able to connect to that driveline. Then you need the computers and wiring to make things work. Because you are using a different makers engine, the protocols will be all wrong so your current transmission and braking will need either custom coding or replacement. That brings you back to state laws, If You pull in with a 323 and tell them, you need to scan it as a BMW. Most are going to fail it instantly, that is because most use the VIN on the car for info and it doesn't match the engine make.
So step one, look at the laws in your are, most cover this type of thing and where they don't there are federal laws on it as well.
Then decide if you pretty much want to build a car from the ground up. I've done swaps over the years and built a lot of race cars. These days, if it's a street car, I'll install a factory rebuild or updated OE style engine in a customer vehicle, I don't want to be stuck in a project for a year or more trying to get it all to fit and work.