You may want to do it that way, but it won't work.
What you need to do -
get a 3/4 way splitter and enough pairs of diplexers.
Wiring - from the OUTPUT side of the DPP44 - put the diplexers in, the SAT input to the output of the DPP44. The ANT input goes to the splitter. The input to the splitter comes from another cable on the output of your modulator. At each end of the cable, you put the other diplexer, with the common going to the common at the DPP44. Sat will go to the satellite reciever, ANT to your OTA inputs device.
If the modulator is the one supplying for the others - then you could use the diplexers to send the signal to the DPP44 , where you would then split and use the diplexer as above.
In any event - the DPP44 will not work to pass the OTA signals in a reliable manner to all the outputs.