Would be better off just keeping the macro at
/cast Blood Tap
/cast use 14
/cast Pillar of Frost
If your on use trinket gives you strength when used, you want that to be popped before you use PoF so you get 20% more strength out of it. It is also not a smart idea to macro PoF into your main attacks, because it would be a shame for it to come off CD, and then you have a phase change in a fight or heavy movement and you don't have the proper up-time to fully utilize the CD.