Adapting VLookup function with if statement in VBA

I'm trying to write a VBA code that would be the equivalent of this excel function for a definite range of cells.

= if(A1="","",vlookup(A1,K1:M2000,3,false))

I want to apply this for range(A1:A15) and insert the function in range (B1:B15) using VBA.