Check out the help on FIND in the visual basic editor. The easiest way to do
this is to click on the word find... No need to select the whole word... and
press F1.

You could also look at http://www.cpearson.com/excel/RangeFind.htm ... Chip
Pearsons site. It's a wonderful excel  VBA reference!

The help will tell you that Find is to look for stuff within a range.

To search  within a range  use something like...

Set rlFRange = Range("invoiceno")
Set rlFound = rlFRange.Find( _
What:="TTT", _
LookIn:=xlValues, _
LookAt:=xlWhole, _
SearchOrder:=xlByRows, _
SearchDirection:=xlNext, _
MatchCase:=False)

Note that I've...
1 Set the range to look in at the top
2 Am NOT using the After parameter
3 Looking for "TTT". This should be replaced by your variable