You can try, depending on side and unit. I can only do it for German forces here, because I lack the detailed knowledge for the other sides:

Depending on your education, you can get into the supplying system. Those mostly needed drivers, officers, guards for the supply depots and mechanics. Officers jobs mostly done pre- war officers, but they were also a variety of different jobs. Aside from the NCOs and Guards, there were Cooks, Shoemakers, financial personnel and many jobs regarding the maintenance of the vehicles (trucks, cars and in some cases planes) and horses. Supply convoys, depots and railway lines were frequent targets of attacks by air, partisans, artillery, and small offensives. Also they were only used on a Division+ Level, Regiments and Battalions had their own systems. It made up around 5-7% of all troops, which made it unlikely to get in without connections or pre-war occupation in a similar field.

Another thing are the engineers (Pioniere). Most of the Engineers were combat engineers, while only a small part was responsible for non-combat duties, like Railway and street building and the (supervision of) construction of defensive lines and positions. The Pioniere were an elite part of the Wehrmacht, so you had to be very fit, both physically and mentally. Also very intelligent. But the chances of avoiding the front lines were slim.

The probably largest non-combat part were the Auxiliaries of a Armoured Division. Mechanics, Painters for camouflage, small electrician teams, cooks and other non combat roles were very common there. This goes as far that of a Tiger Battalion with 879 Men with 45 Tanks, about half the soldiers were assigned to tank and personell maintenance and supply. But again, the headquarters were favourite targets of air and artillery attack.

You can count Staff Officers on A Battalion/Regimental+ Level, because they were also non-combat duties away from the front. But they were often regular officers, that had seen combat before.

There were the Heeresbeamte, The Officials/non-combat organizers. They were often pre-war military personnel, specialized on paperwork and organizing.

So summed up, if you weren't very lucky, you won't be able to avoid any form of combat. For sure, you could end up being in Norway or a meteorologist, but those were very unlikely