You can move the start or end of a range in a forward or backward direction
Code:
rng_Source.MoveEnd Unit:=wdParagraph, Count:=2
rng_Source.MoveEnd Unit:=wdParagraph, Count:=-2
rng_Source.MoveStart Unit:=wdCharacter, Count:=-10
rng_Source.MoveStart Unit:=wdWord, Count:=5