how to get lowest close in the last 30 days with MQL4. THX

 
how to get lowest close in the last 30 days with MQL4. THX
 
zeeye: how to get lowest close in the last 30 days with MQL4. THX

Just a very quick inline solution but you should use a more complete code with proper error checking, so study the documentation on each of the functions and their parameters.

iClose( _Symbol, PERIOD_D1, iLowest( _Symbol, PERIOD_D1, MODE_CLOSE, 30, 0 ) )
Reason: