Copying the wage type /401 to custom wage type

Hi Experts,

i have a query about copying tax wage type /401 to any custom wage type say A001

and process the amount in in this wage type say (-ve)2000 unit and process it through IT0221- subtyp(without tax)

how it will get processed?

my belief- system might just put the amount along side /401 and deduct the tax for the authority, and results can verified in table such as - t5ux0 ?

Please help to clear this doubt

Thanks,