Many thanks for replying.
Yes, I tried many times answering... https://www.codeproject.com/Questions/727990/REGEX-for-validating-URL
I tried at least 8 different times. The preview displayed perfectly, until I actually clicked the 'Post your solution'.
After that, the text was auto-modded, this happenned irregardless of how many pre tags I experimented with.
Im not sure what finally made the difference, I did change the default paste options.
And then I just used the standard pre tag (not ASM,ASP,etc), and it posted just like the preview.
Again, many thanks for the reply!