VLOOKUP error with output of formula using Right(),Len() and Find()

In table A I have a list of codes that contain a numerical component after 1-3 letters. I need to use the numerical value to find the corresponding year via the ranges detailed in table B.

Table A:            Table B:        

Code    Year        Value Min   Value Max   Year
AC19    ?           0           10          2011
ABC2    ?           11          20          2012
AC12    ?           21          30          2013
AFC30   ?           31          40          2014
GXC0    ?           41          50          2015

To separate out the number I have been using:

=(RIGHT(B7,LEN(B7)-(FIND("C",B7)+0)))

(Where B7 in this case is the first code in the table)

This works well as all codes have a C before the numerical component.

I found that using example numerical segments (without using the above formula) I could use VLOOKUP with the "True" flag. However when I attempted to run it using the numerical value generated with the above formula I got a #Ref! error.

Why would VLOOKUP suddenly stop working when using data collected from the formula above?

The ideal output would be:

Code    Year
AC19    2012
ABC2    2011
AC12    2012
ACF30   2013
GXC0    2011