Well, to get the excel data into MySQL, you could export it to a .csv (comma separated value file), and then use PHP to import that into MySQL. The process for doing this is as follows:
Open the file
Use a for loop to go through each line
explode() the line into an array, because it's separated by commas, this is easy (if you've got commas in the data, you can use a tab-delimited file (the tab character is '\t' without the quotes))
Do a mysql insert statement for each line
Check your data in the database to make sure it's correct :-P
I've done this for a bunch of projects that I've had to do, and it takes 10-15 minutes to write the script and debug it (at least for me, I usually have some stupid mistakes in mine). If you've got 1000's of lines, expect the script to run for a little bit; don't kill it in the first 3 seconds if it doesn't complete: it's still working (hopefully it isn't in an infinate loop, though).