I have several Blank rows above each is a row of data (covering columns A-D), what I want to do is populate each blank row with the following:-

Col A - Copy the Text from Row Above
Col B - Insert fixed Text "ABC"
Col C - I wish to remain blank
Col D - Copy the value that is in Col C in Row above to this column

Do above until last Row in sheet (as sheet can have a variable length)

Basically above are Debit and Credit lines,