excel - Matching List of Numbers (with Duplicates) to Strings in another Column -

i have 2 large lists of numbers, 1 duplicates , 1 without:

first list: 2, 2, 3, 3, 3, 3, 4, 5, 7, 7, 7, 8, 9, ...

second list: 2, 3, 4, 5, 7, 8, 9,...

now, each unique number on second list, there column identifier number. example: 2 = a, 3 = b, 4 = c, 5 = d, 7 = e, etc.

what want match unique identifiers on first list on second:

new list: 2a, 2a, 3b, 3b, 3b, 3b, 4c, 5d, 7e, 7e, 7e, etc.

is there easy way this? list has thousands of values cannot manually match them up.

here example of spreadsheet:

column a--column b--column c
----2-------------2-------------a
----2-------------3-------------b
----3-------------4-------------c
----3-------------5-------------d
----3-------------7-------------e
----3-------------8-------------f
----4-------------9-------------g

what want this:

column a--column b
----2--------------a
----2--------------a
----3--------------b
----3--------------b
----3--------------b
----3--------------b
----4--------------c
----5--------------d
etc.

any suggestions appreciated. sorry if wasn't clear request. please let me know if need clarification.

thanks!

if understand correctly, here want:

=a2&vlookup(a2,b:c,2,false) 

this assumes column list duplicates , columns b , c unique numbers paired corresponding letters.

you can drag formula down apply values in column a.