Steps for Implementing Remote Function Modules 
To implement a remote function module in ABAP, perform the following steps:
In the function module Administration screen (transaction code SE37), set the field Can be called via REMOTE CALL. Registering a module as remote causes an RFC stub to be generated for it.
Guidelines for creating function modules in the R/3 Repository are given in the system documentation "Writing Function Modules".
Either you or your system administrator can maintain the RFCDES table using transaction SM59 (Tools