Hi Jean,
first of all welcome in the Navigraph family. We are happy to join us 
To your specific question:
No DMEARCs are included (worldwide) but to code a DMEARC there are a few mandatory parameter which must be set. One of it is, that the ARC must reference to a VOR/VORDME or a TACAN VOR. When this is not the case (as here in the PORCH1B arrival) you can’t code it in the data.
You see the reference navaid on the ARC, it the IKAS ILSDME facility, therefore not codeable.
Other ARCs (which fullfill the requirements) are coded as expected.
Hope that helps, when not please ask again 
Cheers
Richard