I am with Andrew on this one. I would probably use SSIS for this as well. This would allow you to get rid of the stored procedure that calls BULK INSERT too.

The simplest way to get started with SSIS is to use the Import/Export Wizard to import your file into your table. The Import/Export Wizard is asking you questions, but in the background it is actually generating an SSIS Package on the fly. Towards the end of the Wizard you can choose to have the Wizard save the Package that is generated to disk so you can later open it in BIDS and see what was actually produced in terms of SSIS. This will give you a quick entry point into seeing what SSIS can do on a basic level and also gives you a starting point to create a more complex Package.

Once you have the basic Package the Wizard generates saved to disk you can open in BIDS and modify it to do additional things, e.g. searching a directory using a wildc*rd for files to import, or moving the file once to another directory after it has been imported...the sky is the limit.