Select case and Last Cell Problem

Hi

I am fairly new to VBA so be gentle. I have been working on the attached code but am struggling with the CASE SELECT and the loop.

I am trying to search column B of Line List worksheet and if it contains a letter ie is not blank copying it to another worksheet Tags CSV.

I am also trying to loop this process until the end of my data but as my data has gaps between it i need to go to the bottom or (1500 row in column b of line list) move up one until a non blank row is found then return a rown number as a value in order to stop my loop when it gets there.

God I hope this makes sense to you lot as its sending me in circles.

I look forward to your response