Macro: Replace Multiple Cell Values

I have a datasheet, in which i would like to replace data...
for example, A1 has value of 'a.Male' , A2 has value of 'a.Baby'
and the list goes on...

What i want to do is, find all 'a.'s and replace the whole cell with '1' ...

So after replacing the cells A1 and A2 will be '1' instead of 'a.Male' / 'a.Baby'

If this is any help, i posted somethin i wrote... but it has to be repeated many times... i have a large data set.... I need somethin that will do the job with a single press of a button~

Sub Replace()
'
' Replace Macro
' Macro recorded 2006-11-30 by Jae Heon Choi
'
' Keyboard Shortcut: Ctrl+r
'
Cells.Find(What:="a.", After:=ActiveCell, LookIn:=xlFormulas, LookAt:= _
xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:=False _
, MatchByte:=False, SearchFormat:=False).Activate