UFL 'u2lexch.dll' that implements this function is missing

Hello Everyone,

I have a report with a formula field. That formula field uses "ExtractString"  function of crystal report.   I can run the report OK within Crystal Report application  BUT when I 

try to run this report in my C#.NET application  it gives this error

UFL 'u2lexch.dll' that implements this function is missing. Error in File Spine-Labels_CallNumber-ItemDetails-with-Blanks_2x9-v3 {F101E219-FDB8-4DC6-8F37-ABD1D179E19C}.rpt:
Error in formula FictionCallNumber: 
'ExtractString ({Command.CallNumber}, "", " ") + chrW(13) + ExtractString ({Command.CallNumber}, " ", " ")+ chrW(13) + Mid({Command.CallNumber}, 7) '
UFL 'u2lexch.dll' that implements this function is missing.

I found some other threads where people have suggested to copy the missing dll to "BusinessObjects" folder.

But I am receiving this error on my development machine.   I have Full Visual Studio 2010 installed, Crystal Reports 2008 as well.  and I can find that particular dll [u2lexch.dll] on my machine in few places.   so dll does exist but I still receive this error.   Having full visual studio and crystal reports, I would assume the dll would be in right place where its supposed to be.

Any ideas on this one?

Thanks