convert numbers to text and maitain number of digits including preceeding zeros

HI

I need to convert a column of numbers containing three digits (ie 001, 002, 003) into text, and maintain the zeros preceding the the non-zero digits. How can I do this?

OR

I have two columns of numbers, both sets with zeros as the initial digit.  HOw can I combine the two columns?  I see how  to do it with both columns as text, but not as numbers.

I have  3,000 rows of data, so don't really want to convert each cell by hand with an apostrophe.

col A   col B     desired output

01      001         01001

01      003         01003

04      052         04052

15     167          15167

Thanks