You can use a variable to do it. You don't mention what your If statement is, so I just threw one together:
<font face=Tahoma><SPAN style="color:#00007F">Sub</SPAN> AddSheet()
<SPAN style="color:#00007F">Dim</SPAN> NewSheet <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Variant</SPAN>
<SPAN style="color:#00007F">If</SPAN> 1 + 1 = 2 <SPAN style="color:#00007F">Then</SPAN>
<SPAN style="color:#00007F">Set</SPAN> NewSheet = Worksheets.Add
NewSheet.Name = "This is the New Sheet"
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">If</SPAN>
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN></FONT>
If you need to, this can also be set up so that the name of the sheet is determined by user input instead of 'static' in the code as it currently is.