We can Use the Following Function Module to convert from one Currency value to others.
In following function module we need to pass Foreign currency, Local Currency type_rate: 
Type of rate:
M=Average rate 
G=Bank buying rate 
B=Bank selling rate
We Get Exchange rate for that day, foreign factor, Local factor.
And Foreign currency can be calculated as below mentioned in IF ENDIF
 
Coding:
DATA: l_er TYPE tcurr-ukurs, 
             l_ff TYPE tcurr-ffact,
             l_lf TYPE tcurr-tfact,
             l_erate(12) TYPE c,
CALL FUNCTION 'READ_EXCHANGE_RATE'
      EXPORTING
           date = sy-datum
           foreign_currency = wa_bseg-pswsl
           local_currency = c_euro
           type_of_rate = 'M'
      IMPORTING
           exchange_rate = l_er
           foreign_factor = l_ff
           local_factor = l_lf
      EXCEPTIONS
           no_rate_found = 1
           no_factors_found = 2
           no_spread_found = 3
          derived_2_times = 4
          overflow = 5
      OTHERS = 6.
IF sy-subrc = 0.
   l_erate = l_er / ( l_ff / l_lf ).
   wa_itab-wrbtr = wa_itab-wrbtr * l_erate.
endif.


Serkan AKKAVAK
Computer Engineer
ABAP Developer & SAP MM SD Consultant
Contact : serkurumsal@yandex.com