What is the coding for a 12 day EMA?

 

I am so new to proraming and keep getting it wrong . I'm wondering if anyone would be kind enough to give me the coding for a 12 day EMA. If you give me the syntax for these calculations in MQL4, it would help as well;

1. 12 day EMA - 26 EMA

2. William's %R 14 day Simple MA

Also, I want to view my 12 day EMA - 26 EMA as a line and a histogram. What should I do to convert it from one form to the other?

Thank you ever so much.

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