replacing value

when I copy and paste certain data, there's always certain values that need to be changed.

ex

A100= daveyc18

B100 = 1,000

but I always need to replace B100 with = 20,000 every day.

in OTHER rows,

A200 =batman
A201 =batman
A202 = batman

B200 = 1,000
B201 = 1,100
B203 = 1,200

And I need to manually change B200-203 to 2000,3000,4000 every day.

I can this can be automated, but the trick here is the row numbers change every day. for example, the daveyc18 row can be 150 one day, and the next day it can be in row 160.

so, i'm wondering replacing these numebers can be done automatically...again, the numbers that are using to replace the original values are the SAME every day (e.g, daveyc18 ...always using 20,000....batman, always using 2000,3000, 4000)