Have you checked Infotype 0587...
There it self you can mention Eligible pay or PF basis which ever is less....
Check tables V_T7INF1 where we will mention /3xx wages or MFxx wages or customer wages copied from MFxx wages.
For PF calculation no need to write PCR, Its a statutory deduction.
If we opt for Eligible pay or PF basis which ever is less in 0587 Info type, INEPF Payroll function checks PFBAS constant in V_T511P table which will be a value of 6500 and calculates PF.
Like If basic = 10000, PF=780 ie. 12% on 6500
If Basic = 5000, PF=600 ie 12% on 5000
And for retro wages like /ZF5, we have to insert our wages in PCRs IN42, IN43 and IN44. In these already /3Fx wages will be there by standard.
Regards,
Srikrishna