Do Find & Replace multiple times using data in Col B for find & data in Col C for replace

In column A I have over 250 pieces of data - odd data in that it is separated into 4 parts because there a 3 periods in each piece of data.
In columns B & C I have about 90 rows of Find this Data (Column B) and equal number of rows of "change to" data in column C
I want all 4 parts to contain 3 digits
For example in B I have find .0. and in C1 I have .000. as the data to replace .0.
Want the macro to run and run until ever possibility in Column B has been checkid out.
Is this do one thing after another - row after row called a loop?
Thanks