If you want four separate parts :

First Part:

SUBSTRING(IP,1,FINDSTRING(IP,".",1) - 1)

Second Part:

SUBSTRING(IP,FINDSTRING(IP,".",1) + 1,FINDSTRING(IP,".",2) - FINDSTRING(IP,".",1) - 1)

Third Part:

SUBSTRING(IP,FINDSTRING(IP,".",2) + 1,FINDSTRING(IP,".",3) - FINDSTRING(IP,".",2) - 1)

Fourth Part:

SUBSTRING(IP,FINDSTRING(IP,".",3) + 1,LEN(IP) - FINDSTRING(IP,".",3))

If you want the whole string in 3 digit placeholder format:

(LEN(SUBSTRING(IP,1,FINDSTRING(IP,".",1) - 1))==1?"00": (LEN(SUBSTRING(IP,1,FINDSTRING(IP,".",1) - 1))==2?"0":""))+SUBSTRING(IP,1,FINDSTRING(IP,".",1) - 1)

+"."+

(LEN(SUBSTRING(IP,FINDSTRING(IP,".",1) + 1,FINDSTRING(IP,".",2) - FINDSTRING(IP,".",1) - 1))==1?"00": (LEN(SUBSTRING(IP,FINDSTRING(IP,".",1) + 1,FINDSTRING(IP,".",2) - FINDSTRING(IP,".",1) - 1))==2?"0":""))+SUBSTRING(IP,FINDSTRING(IP,".",1) + 1,FINDSTRING(IP,".",2) - FINDSTRING(IP,".",1) - 1)

+"."+

(LEN(SUBSTRING(IP,FINDSTRING(IP,".",2) + 1,FINDSTRING(IP,".",3) - FINDSTRING(IP,".",2) - 1))==1?"00": (LEN(SUBSTRING(IP,FINDSTRING(IP,".",2) + 1,FINDSTRING(IP,".",3) - FINDSTRING(IP,".",2) - 1))==2?"0":""))+SUBSTRING(IP,FINDSTRING(IP,".",2) + 1,FINDSTRING(IP,".",3) - FINDSTRING(IP,".",2) - 1)

+"."+

(LEN(SUBSTRING(IP,FINDSTRING(IP,".",3) + 1,LEN(IP) - FINDSTRING(IP,".",3)))==1?"00": (LEN(SUBSTRING(IP,FINDSTRING(IP,".",3) + 1,LEN(IP) - FINDSTRING(IP,".",3)))==2?"0":""))+SUBSTRING(IP,FINDSTRING(IP,".",3) + 1,LEN(IP) - FINDSTRING(IP,".",3))