technique problem

jsut a general quesiton, Im trying to play a part of a solo where I have to do a section, and I could never play i rite, Im thinking maybe im uing the wrong fingers so im wondering, how would you guys play the following?

2------18 p 15-----------18 p 15--------------18 p 15------------------
3----------------17------------------17--------------------17

its not only two times, you repeat the pulloff and the note about 6x

its played kinda fast, listen to near the end of the fills before the song ending solo begins in white room

anyway, i play this by putting my index on 15 and use my middle to pull off on 18 and swing it down to 17, keeping my index planted on 15

i hope its only a technique problem

thanks