To remove letters

One method would be to find the position of the first letter in the string that is not in the first position and then use that value to extract the string from the start to the determined value. 

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjQyNjE1U4rViVYKNjUzgjDMTM1MHNPcwBxHU5NkMMPI0MzUBMwCylqYJJUpxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
    #"Added Custom" = Table.AddColumn(Source, "TextLocations", each List.Min(List.RemoveItems(Text.PositionOfAny([Column1], {"a".."z", "A".."Z"}, Occurrence.All), {0}))),
    #"Added Custom1" = Table.AddColumn(#"Added Custom", "NewColumn", each try Text.Start([Column1], [TextLocations]) otherwise [Column1])
in
    #"Added Custom1"

The code above walks through the steps. 

Hope this helps.

Hi Anonymous 

You can try the following code.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCjY00TMw9HUOU4rVgfG8lGJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each Text.Start([Column1],List.Max(Text.PositionOfAny([Column1],{"0".."9"},Occurrence.All))+1))
in
    #"Added Custom"

Output

Best Regards!

Yolo Zhu

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