Interactively, if I turn off the new parameter interface, I can copy & paste the value of one parameter, into a new parameter. Anyone know of a way to do this in a mapkey? If I tried to do this with a trail file it would retain the value recorded in the trail file, so I don't think that's going to work for me.
Have you tried using relations? You could set the new parameter equal to an existing one and then delete the relation. If you have existing relations, you'll probably want to export them, create the new parameter with it's relation, then re-import the original relations (which will delete the parameter relation at the same time).
Do you want to use the new UI or the old?
The new UI records if you press Ctrl+C and Ctrl+V, so yes, you should be able to do this with just a mapkey.
The old UI I think doesn't allow copy/paste, you have to get the value some other way. Maybe parameters->Info and then read the value from the Param.inf file?
Something like this for the new UI:
mapkey $F2 ~ Command `ProCmdMmParams` ;\
mapkey(continued) ~ Select `relation_dlg` `ParamsPHLay.ParTable` 2 `rowPARAMETER_1` `value`;\
mapkey(continued) ~ Key `relation_dlg` `ParamsPHLay.ParTable` 37945347 `Ctrl+C`;\
mapkey(continued) ~ Select `relation_dlg` `ParamsPHLay.ParTable` 2 `rowPARAMETER_2` `value`;\
mapkey(continued) ~ Key `relation_dlg` `ParamsPHLay.ParTable` 39190550 `Ctrl+V`;
Just replace "PARAMETER_1" and "PARAMETER_2" with yours and try it.
looks as if there have been two good advices.
Have you been able to successfully make use of them.
If you have the time, please let us know your experience and mark the answer as correct, which you finally adapted.