CAD tip # 12432:

The reg.exp. principles in the search portion is quite simple - the parentheses "()" capture the individual character groups, the braces "{}" define the number of characters. In the replacement portion then you can reference the captured groups with "$1", "$2" etc. (in the capture order). The code "\d" means a digit, the dot "." then any character and the plus "+" means any number of repetitions.

See examples:

' 770203010005.ipt --> Part number 77.02/03.01.00.05
' EP354-J12(C).ipt --> Part number J12-C/A354
docname = ThisDoc.FileName(False)
FN = System.Text.RegularExpressions.Regex.Replace(docname, "\b(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})", "$1.$2/$3.$4.$5.$6")
'FN = System.Text.RegularExpressions.Regex.Replace(docname, "\b(.{2})(\d+)\-(.)(\d+)\((.+)\)", "$3$4-$5/A$2")
iProperties.Value("Project", "Part Number") = FN
iLogicVb.UpdateWhenDone = True