Italy Corps starts in 1940 in North Africa during the Border Raids. In my opinion, the official Afrika Korps' grave error was to let the opportunity pass by to include scenarios before the Afrika Korps' debut under the command of Rommel and thus to deny Italian units from gaining experience. This might be a reason why Italian units are disbanded or remain undeployed during the course of that campaign.
Campaign:Italy Corps contains the following scenarios - British Raid, Fort Capuzzo, Nezuet Ghirba, Frontier Wire, Sollum, Buqbuq, Sidi Barrani, Operation Compass and Beda Fomm. After Beda Fomm, the campaign continues in Afrika Korps.
1) Back-up the Panzer Corps/Data folder before proceeding
2) Extract the rar file in either
\SteamLibrary\SteamApps\common\
for the Steam version of Afrika Korps
OR
\Slitherine\ (or wherever you have installed Panzer Corps)
for the non-Steam version of Afrika Korps
3) Start the game, chose Afrika Korps and start playing Italy Corps, the 9 scenario campaign prior to the Afrika Korps campaign.