How to add a hyphen after 4 characters in a column

[KA95]

Hi there, I have a problem with a column that looks like this: 

Is there any way I can add a hyphen "-" after 4 characters in every row of this column? so "201108" becomes "2011-08" so it's a lot more readable and could potentially be converted into a date column? 

[Vijay_A_Verma · Accepted solution]

If you need in a custom column, use following formula

= Text.Insert([Month of Year],4,"-")

If you want in column replacement, then use following statement where Source should be replaced with your previous step

Table.ReplaceValue(Source,each [Month of Year],each Text.Insert([Month of Year],4,"-"),Replacer.ReplaceValue,{"Month of Year"})