Parked Document approval workflow

[Ulagapiragasam Vanathy (RBAU/ISY)]

Hi,
 
I customised the  Approval groups, paths, procedure and defined the users in
IMG (Financial Accounting>>Financial Accounting Global
setting>>Document>>Parked documents) for approving the Parked Documents.
I am using the subworkflow WS10000055 (account assignment)
 
I have got 2 issues here,
1. Where do we define the account assignments in the config?
2.  When I created a parked invoice I am getting the following message
Expression '&ACTIVITY_000043_TASK&' for task: Error during evaluation or
incorrect data type
Element SUBNR not in source container. Worklfow 'Document Parking(Frame),
Parallel'
 
Thanks
Vanathy