the last cell  thing was my first question to the list as well.

---------------
Last Cell -

LastCell = Worksheets("<WorksheetNameGoesHere").Cells.SpecialCells
(xlCellTypeLastCell).row
----------------------------

String Operation you're looking for is:

substitute(string, old bit, new bit)

or
substitute(" hello world  ", " ", "")


Not sure about the best way to find, it's prob some kind of lookup
but it's not something I use much myself.