Assigning material and serial number to equipment

Hi,

Is there a way we can assign an existing serial number data (already created automatically during stock upload/receipt) to an existing equipment? Besides trying in equipment master change mode in Serialization Data tab, I have even tried to assign the material and serial no. while an equipment is being created (IE01). But in both the instances, it is not being allowed (system generates an error “serial number already exists for material”).

I have:

1. Created serialization profile with
   1. MMSL as one of the procedures
   2. Automatic generation of serial numbers
   3. Proposal w/o equipment
2. Created material with
   1. Split valuation
   2. Material type: ERSA
   3. Assigned serialization profile to material
3. Extended material to valuation types (new/damaged/repaired)
4. Created initial stock (501)
5. System is automatically creating serial numbers (as expected)

Is there a way to assign the combination of material and serial number to an equipment which has already been created in the system.

If not do I then go ahead with creation of serial no.data during material assignment to equipment as is being allowed by the system?

Thanks