Trims and Sub Trims

I want to transfer the value of a trim to a sub- trim.
My trim (on elevon) makes the neutral position to be -6%
Is there a way to calculate the value to add to my Subtrim which is -18.3
In the ini file The trim is -66,0,0 (why 3 figures) and the subtrim -183
Should I add -66 to -183 to transfer my trim to my subtrim ?
Is there a way to see the value of the trim (-66 here) except looking into the ini file ?

Sorry if this question has already been treated but I have not found in the forum.

Morlacus

that is a good question, btw it would be an excellent feature, some function in the Tx model menu transfer trim to Subtrim, in order to set all trims to middle position, when the model has got it's maiden.

Agreed, but I am not so demanding...

I would be pleased if I was assured that my assumption that adding the trim and sub trim values of the ini files and putting the result in the subtrim value and zeroing the trim value would correctly transfer the trim value to the sub trim.