Retainage - where CIS is involved

Hi I am having a nightmare with quickbooks and sending myself round in circles when I am sure there must be an easy solution staring me right in the face, so I would love some help if anyone else has dealt with this?

1) in 2023 a retainage amount was kept back by a customer for 2 years. - it was deducted from the invoice on a line called retainage (asset account which is where it has sat until now).

2) I now need to request these funds from the customer - which sounds simple - except I need to enter it as a CIS Standard entry (so all the relevant internal recording of CIS takes place) - so how do I get rid of the amount showing in the retained asset account. If it wasn't CIS it would be added direct to the invoice - but because I need to use the CIS standard I cant do this.

Am I missing something simple here?