Is there any Army Regeulation for misplacing any gear you sign for, like from CIF or on a hand receipt?

There are time lines for field losses. I don't know the actual Army regulation but you can look that up
on Google if it's that important to you. If you lost it, you are responsible. If you had it stolen you are most likely still responsible. If it was stolen on a federal installation and unless there is evidence of forced entry and the gear was double secured on government property you might have a good chance to have it paid for by the government. Most of the time service members will be responsible.

There's several different regulations depending on what property is lost. AR 700-34 covers OCIE (personal gear), your best bet though is to read through AR 735-5. If the property that is lost is in excess of a certain $ value, on the commanders property book, sensitive in nature, or meets other criteria an investigation is required. The procedures for such an investigation can be found in AR 15-6.

Gear adrift is gear a gift