Combining data from two fields into one

We have recently purchased a mail machine that allows us to import Excel files. Our problem is that the requirement for the street address is that it is all in one cell. For instance "123 Happy St.". Our existing database only allows us to export it as two seperate fields, for instance "123" and "Happy St.". We are trying to merge the data together with out going through the 10,000 addresses that we have on file manually by exporting to a tab delimited text document & manually deleting the spaces in between, then importing the file back in to Excel. The only thing that I have found that seems to apply to our problem is the cell merge feature which gives us the message of "The selection contains multiple data Values. Merging into one cell will keep the upper-left most data only". If I proceed, it deletes all of the data. Please help me. Thank You.