Thanks for you first post zept and welcome to the site.
1) The name button simply formats a cell (i.e. automatically subscripts) it appends " =" to the cell and right justifies the cell. On every 'redraw worksheet equations' XLC will check that this cell continues to be formatted in this way. Most of the time this is the behaviour you need.
From time to time it is not what you need, your example being a good case of this. So now you need to name your cell manually and append it with "=" (notice that the space character is missing). XLC will not try to make this cell conform to the automatic subscripting standard. In your case enter "u(d)=" into the cell and right justify the cell if you want - that's it - you don't use the 'name' button at all. XLC will drag this name with the its particular format into equations. see the diagram below:

2) You will see that there is a formula in cell C3 containing an EQS() function. The parameters of this function for the equation control string. Change "EqnPrefix=Eqn." "EqnPrefix=" to turn off equation numbering. The defaults for the equation control string are set using the 'about XLC and settings' button.

I hope this helps.