Autofill if blank from random cell in chosen column

Hi all,

This is my first post so bear with me. I'm usually good at finding out how to mold a formula to my suiting but i'm at bit of an impass:

I would like a formula to autofill all blank cells within (Data!J,1) to (Data!J, LR) with a random, non-empty cell from column DATA!B. Here is what I have so far:

Dim i As Integer

For i = 1 To LR

If Range("DATA!J" & i).Value = "" Then Range("DATA!J" & i).Value =xxxx

next i

end sub

I don't know what to put in for "xxxx". "xxxx" should be a value of a random, *non-empty* cells in the Data!B column

for the non-empty condition i think i should use: Range("DATA!B" & Rows.Count).End(xlUp).Row) in order to set a range of cells with data in them

I don't know where to go from there though.

Please help!

Thanks, and I'm happy to join this forum!

-J