dynamic mapping based on variable

SOURCE

i have source csv with State , Amount columns

DESTINATION

i have 2 Region Tables with

Table Name: USA_Region

Columns: USA_State , USA_Amount

Table Name: UK_Region

Columns: UK_State, UK_Amount.

REQUIREMENT

Based on the parameter set in config table, i need data to insert data into destination table.

i have set the table dataaccess mode as Table name or view name variable so that i got the destintaion table set.

how to set the variable mapping for columns as Input column name is not mapped to output column name based on my source table?  I need to change the name of the input column like USA_ or UK_ so that my columns can be mapped against destination

ShanmugaRaj