Linking Requirements to Source Code

My company is moving towards using DOORS for requirements management.  One of our needs is that we need to link our requirements to the source code level - to specific functions.  We do not have any experienced DOORS users and have not been able to determine if DOORS has this capability.  We need this for DO-278 compliance.  

If DOORS does not have this capability, is there an add-on that would allow us to achieve this functionality?  

I know one issue we have is the DOORS database is maintained in one "location" and the code repository in a separate "location."  I am not sure how much of a challenge that will create.

I appreciate the help.