You can use text expressions find(), mid() to separate values from your string "L3C2H99P40".
However it would be much easier to use one or several dictionaries.
For example, write this data to the dictionary:
Key="A_Level", value=3
Key="A_Health", value=100
Key="B_Level", value=7
Key="B_Health", value=34
To save it to local storage: LocalStorage set item "SaveGame" to Dictionary.AsJSON
To load from local storage: LocalStorage on item "SaveGame" get: Dictionary load from JSON LocalStorage.ItemValue