Replacing special characters

Hi Experts

I have reqwirement, Purchasing data, using data source 2LIS_02_SCL (Purchasing Data (Schedule Line Level)) fails frequently because it brings unassigned "#" values for the object ZQUOTNUM (Quotation number).

To eliminate the unassigned "#" values automatically write a routine at transfer rules leval.

I found out one function module SCP_REPLACE_STRANGE_CHARS but how to use this function module

Regards

Venkat Marneni