Find first cell then fill the cells until last used row

[urobee]

Hy,


My target is to fill the cells in column B with a formula from the first empty cell for the last used row.

I can fill the cells from a given cell until last used row with this code:

Dim Lastrow As Long
Lastrow = .Range("A" & Rows.Count).End(xlUp).Row
With shBom
'other parts of the macro
	.Range("C2:C" & Lastrow).FillDown
End With

And I can find the firts empty cell in a row:

Dim Firstrow As Range
Set Firstrow = shMySheet.Range("B1").End(xlDown).Offset(1, 0)
'other parts of the macro

But how can I combine this two?
(the first and a last used cell is change often so it's not acceptable to set a constant cell address in the code)

Thanks!

 

[footoo]

Dim bRng As Range
Set bRng = Range(Firstrow, Cells(Lastrow, "B"))

 

[urobee]

Thanks,

I needed to modify your code but it is good for a start!