Capturing Salaries as costs in projects

Hello everyone,

I have a situation where my major cost component is internal manpower cost eg. salary.

Now i want to post this cost to PS as cost monthly. We have not implemented payroll here.So how will I capture this cost. I have already tried assigning manpower cost at activity level (activity type in workcenters). But this is not very feasible solution, since I have to change activity type costs depending on manpower.

Any help would be highly appreciated.

Sincerely,

Aji Kurian Mani