I have an issue in Crystal reports that I think is pretty easy but it is stumping me.

I have a table with all doses billed (we'll call it Billing) to patients and each supply or drug is assigned and eight digit code(RPC) that is stored as a string (not my call). I want to select for only those items in another database (we'll call it Drugs), it's the same number as in the previous EXCEPT that it is a seven digit code. I have it stored as a string. I was unable to do a compare with one of them being seven digits and one being eight. I have a COPY of drugs that I made and eight character string.

So here is the basic concept

RPC Cost Patient
12354540 $1.33 someone
98778780 $4.22 someoneelse

RPC Name
1235454 TooExpensiveDrug
4658456 NotTooExpensive

I'd like the output to be like:
RPC Name Cost
1235454 TooExpensiveDrug $1.33

I tried comparing them and they failed for obvious reasons so I tried:

left({Drugs.RPC},7)=Left ({Billing.RPC},7 )
and that failed, so I tried

right({Drugs.RPC},7)=Left ({Billing.RPC},7 )
and that failed, so I tried

{Drugs.RPC} & '0'={Billing.RPC}

I was wondering if anyone could tell me how to compare these to make them match.