Retention or holdback in sap mm

Hi

I have an issue of setting up retention senarion to my client.

can someone give me step by step procedure of retention in ECC6.0 ehp 5

i have 90% to pay to the vendor while 10 holding back need to be paid after 6 months.

but when i post the MIRO systm should keep this 10% in special G/L .

thanks in advance for helping me.

regards

Shahab

Message was edited by: Jürgen L