Disliked{quote} i have tried, but i have problem:here what i done: 1) put dll in C:\Users\Administrator\AppData\Roaming\MetaQuotes\Terminal\287469DEA9630EA94D0715D755974F1B\MQL4\Libraries 2) try to attach script ( yet compiled) in generic chart, but unfortunately i wrong something and script not remain attached to chart 3) more seious problem: tried to cut and paste unicode mql in generic EA, but a lot of error happen when i try to compile mql4: main error is that "function start already exixts". i think the problem is that i don't understand where paste...Ignored
So, you need to learn about general MQL program structure and what functions do what. Then you need to decide what your actual use case is regarding "calling one MQL program from another". I don't see a good reason to call the PeriodConverter from an EA, instead you should just directly execute the PeriodConverter if you need it. You don't need an EA for that.
Typically you want to call another program if the currently running program can not do what you want to do. For example you may want to call a script from an indicator because the indicator cannot trade. Or you may want to run time-consuming calculations in a background task (as a script) because indicators run in the foreground (the UI thread) and block the application.