Selecting letters/characters/numbers separately for a filter

Hi there, does anyone know if there is a method to filter by characters/letters (or it would suffice to filter only by numbers).

To explain the situation I have a sheet that is created via a macro from a text file but before I add a formula to the sheet (involving a lastrow code) I need to take out quite few rows of needless text i.e. headers, page numbers, file details, dotted lines from where the page breaks were on the text file etc. to cut down the rows of calculation. Obviously the number of rows varies with each load of a new text file.

Now what I do have is a column (C) where all the rows I need to keep are a numeric value and all the lines I need to lose are either characters or letters.

I can apply an autofilter for each different character/word/partial word but there are a fair few I would need to put in so I was wondering if there is already a method in excel for selecting letters/characters/numbers separately to use with a filter.

Please note that it needs to be added to a macro and needs to work in Excel 2003.