Recording third party wages

We're starting to use a third party administrator (insurance) to pay our employees that are on short-term disability. The TPA withholds the federal and FICA taxes but they do not file the taxes on our behalf, instead they mail us a check for the taxes withheld. What is the best way to record through our PeopleSoft payroll so as not double their taxable wages but to include the taxes to be filed on the 941's? Looking for any assistance or companies that also have this process for disability payments.