Macro/VBA to Fill blank cells ABOVE a value

[Wheelie_Awesome]

This is a weird one, I didn't know how to title it.
On a certain data set that I export, the data only includes an Account number on a "subtotal" row.
Column A is "Account ######". I first do a text to columns to break those apart. Not an issue already done in VBA.
Now Column A is just "Account" (Which I no longer really need but not the issue I'll delete later) and Column B contains the Account Numbers.

The issue is, these account numbers are only on what are "subtotal" rows of the dataset. For example in Column C, lets say I have Dollars.
So example: A2:B5 are blanks. A6 and B6 will have Account and Number like stated above. C2:C5 will have dollars amounts, and C6 will be the sum of the dollars.
What I'm trying to do is get the account number filled in B2:B5.

This will be repeated down the file, for 10's of thousands of rows. hundreds of accounts.
Each data pull will be different row variations.

Hopefully that explains it well enough. Is there a possible solution to this? Thank you.

Here is an example with colors to represent where the numbers need to go.

 

[Fluff]

How about

Sub Wheelie()
   With Range("B1", Range("B" & Rows.Count).End(xlUp))
      .SpecialCells(xlBlanks).FormulaR1C1 = "=r[1]c"
      .Value = .Value
   End With
End Sub

 

[Wheelie_Awesome]

How about

Sub Wheelie()
   With Range("B1", Range("B" & Rows.Count).End(xlUp))
      .SpecialCells(xlBlanks).FormulaR1C1 = "=r[1]c"
      .Value = .Value
   End With
End Sub

That worked! Are you able to explain what that's actually doing, just so I can maybe learn a little and not just copy paste. haha. Thank you.

 

[Fluff]

It's putting a formula in the blank cells that looks at the cell below & then converts it into a value.
So the formula for B2 would be =B3