Sometimes it seem to help just to write down the thoughts... Attached my results, in case anybody want to mod them.
The M812 is my prototype of eight macros. By setting the Probing Axis (PAx)axis, the Stepover Axis (SAx) and the directions (DP-direction of probing, DS-direction of stepover) the code will then sample the data from some user-DROs and then probing an edge until the end is reached or the required distance is finished. (Ooops, one "bug" still in there: when determining the number of repetitions it uses always the Y-lenth DRO 1007. Have to select between 1006 and 1007 here depending from the axis to be probed...)
I made a screem with eight buttons and the DROs to group all probing related controls.
The M822 code is for determination of the probe tip diameter. I made a aluminum rectangle plate (88x70mm, out of the bin), milled a 50mm dia hole into it and placed it on the surface. From any starting point of the probe tip inside the hole it probes the hole to get the center, then probes the diameter in X and Y, calculates the probe tip dia and finally probes the outer dimensions to double check the settings.
Cheers
Holger