Hi there. Well, yes you can but you might end up wishing you hadn't started.
In 1998 Peugeot changed the upper right-hand engine mounting, the bracket on the body is different and there is no mounting that made by Pug to mount the DW10 (2.0HDi) onto the old bracket. So you'd either have to fabricate something or change the bracket on your car.
Pug did start fitting the DW10 into the last of the D8 (what your car is) in 1999, after this the D9 was multiplex, so you'd need the ecu from one of these, if you can find one.
The 1.9 is a cable clutch, the DW10 is hydraulic. You'd either need the sealed hydraulic system from a D8 2.1 or DW10, or to use the later system you'd have to change the pedal box, clutch pedal and brake reservoir.
The 1.9's BE3 gearbox is a rod gearchange, the DW10's ML5T is cable, you'd need to change the gearstick. Oh, and driveshafts obviously.
In 1998 they changed the fuel tank, you'd need the later tank in order to fit the DW10's lift pump. Probably.
You'd also need the speedo sensor and control box from a 2.1, all the plumbing and pipework from a DW10 incl. exhaust, cooling system, engine harness and probably other stuff I haven't thought of.
Or you could sell the DW10 on ebay and buy another 1.9 with the proceeds. I know which I'd do
Still, it was interesting to go through Service Box and see what the differences were. I also think the answer was a bit more helpful than "oh probably, but I don't think it'd be worth it", which was my initial response.