Replace In String

I have a series of displays that may, or may not, contain specific characters within a string that I need to replace.

For example:

Jones - 05002

Smith - 09001

Unger - 10101

Should be 

Jones - B002

Smith - C001

Unger - D101

IF string contains "- 09" then replace "- 09" with "- C" elseif string contains "- 05" then replace "- 05" with "- B" etc.