Create a stored procedure that takes one parameter, and pass the value of the txtPathfile into the parameter.
If you are wanting to update an existing record, use an update statement like this:
update TABLENAME set FIELDNAME = @P_PathFile
If you are wanting to insert into a new record, use an insert statement like this:
insert into TABLENAME (FIELD1, FIELD2,...,FIELDN) values (VALUE1, VALUE2, ..., VALUEN)