Logic of Excel Shhet

Dear Gurus,

How to put Excel Logic in ABAP Code.

Ex : Excel Logic : (I3/(1-(0.09/4))^(MIN(20,ROUNDDOWN(($D$1-D3+1)/91,0))))-I3

Ex : ABAP Code :G_TAB-INTER = ( G_TAB-PVACQ / 1 - ( '0.09' / 4 ) ) ** ( MIN ( 20, FLOOR ( ( P_BUDAT - G_BSIK-BUDAT + 1 ) / 91,0 )) ) ) - G_TAB-PVACQ.

Correct me