How to generate automatic Family Unique Group ID

Dear Forum

I want to create an automatic ID match with two names. Model sheet has been attached for your kind reference.

Describing requirement:

I have a master data set, which catches regular visitors of health center. Column C and M has a couples name. For example: If Column C has husband name, then Column M would have wife name. It happens wise versa also.

Now I need a automatic family unique ID should be created for each family based on name matches with C and M. I have tried the following code. But no positive results.

"Range("M" & Target.Row) = Evaluate("=IF(V" & Target.Row & "="""",IFERROR(INDEX,(M" & Target.Row & ",MATCH(TRUE,IF(C" & Target.Row & ",C" & Target.Row & "),V" & Target.Row &",V" & Target.Row & ")<>""""),0)),""""),IF(MATCH(V" & Target.Row & ",C:C,0)>ROW(M" & Target.Row & "), "OD/GJM/FID"&TEXT(MAX(IFERROR(RIGHT(M$2:M2,MATCH(V" & Target.Row &"),C$2:C2,0))))"

Kindly do the needful.

Thanks in advance.