user exit for vf01 or SAPMV60A

Hi to all

I have find out the list of user exit for VF01. but i can not understand how can i find these exit point in program

for example  SDVFX004 (User exit G/L line in transfer to accounting ). if i search in program SAPMV60A then it is not found. so expert please reply as quick.what is going on.