Dunning procedure DL1 by Dunning thru Invoicing , Can I enforce DL 1 in FPVA if current DL 3 or 4

Hi FICA experts,

my client has on of the dunning procedure dunning level 1 will be by dunning through invoicing,

and then next levels will be (2, 3, 4) by Regular Dunning ....and in next invoicing they will reset to dunning level 1.....

but customer wants to set level 1 in regular dunning process when there is a dunning lock expired between last Invoicing date to today's date and current DL 2/3/4,

I tried in debug mode to update the DL 1, I am receiving following error message

"In Customizing it has been defined that with dunning procedure GS dunning level 01 can only be generated by an external program and not by the dunning run."

Can I achieve this by FQEVENT 304 ?

please suggest for any alternative solution if this does not work.

thanks in advance.

Ravi