Excel VBA

Hi Guys

This is probably quite a basic IF function question here, but I seem to be struggling with this a lot!

What I have is the below:

Sheets("AUD").Select
Range("D4").Select
Do Until ActiveCell.Offset(0, -1) = ""
ActiveCell.FormulaR1C1 = "=CONCATENATE(RC[-3],RC[-2],RC[-1])"
ActiveCell.Offset(1, 0).Select
Loop
If ActiveCell.Offset(0, -1) = " " Then
ActiveCell.Offset(3, 0).Select
End If
End Sub


What I'm trying to achieve is the following; to concatenate the prior 3 cells, until the activell offset (0,-1) is blank, BUT if the activecell offset(0,-1) is blank then to jump down 3 cells and continue to concatenate the prior 3 cells. I'm a little unsure to what formula to use as and when it comes to the end of concatenating the data.

Any help is greatly appreciated.

Thanks!

Freddie