Using a Codepage in String Conversion Operations
When converting string variables into arrays of char type and back, the encoding that by default corresponds to the current ANSI of Windows operating system (CP_ACP) is used in MQL4. If you want to specify a different type of encoding, it can be set as additional parameter for the CharArrayToString(), StringToCharArray() and FileOpen() functions.
The table lists the built-in constants for some of the most popular code pages. Not mentioned code pages can be specified by a code corresponding to the page.
Built-in Constants of Codepages