Good Afternoon, Everyone!

I’ve searched through the forums for answer, but everything I’m coming up with is short of what I’m trying to achieve, but great starting spots… I just can’t figure out how to utilize what’s out here to finish it.

Let’s say that I have a CSV file that has 3 columns of data, as show below:

54,R,5,MEETINGS

54,R,25,INDLB

54,R,7,MISCMTA

56,R,9,MAINT

56,R,5,INDLB

56,R,1,MAINT

57,R,1,MAINT

62,R,5,EN

62,R,5,INDLB

62,R,1,MEETINGS

I need the PowerShell script to do the following: If Column1 equals 54,56,62 (and other specified numbers) AND Column4 equals MEETINGS, MISCMTA, MAINT (and other specified codes) THEN change Column4 to UNKNOWN.

What we would end up with is:

54,R,5,UNKNOWN

54,R,25,INDLB

54,R,7,UKNOWN

56,R,9,UNKNOWN

56,R,5,INDLB

56,R,1,UNKOWN

57,R,1,MAINT

62,R,5,EN

62,R,5,INDLB

62,R,1,UNKNOWN

All help is GREATLY appreciated!