This example moves the selection after consecutive tabs.
Selection.MoveWhile Cset:=vbTab, Count:=wdForward
This example moves aRange
while any of the following (uppercase or lowercase) letters are found: "a", "t", or "i".
Set aRange = ActiveDocument.Characters(1)
aRange.MoveWhile Cset:="atiATI", Count:=wdForward