How to compare a string weather is equal or not equal to a cell of the excel sheet


Here I am trying to store the resultant date in the data row. where I want to get the data that the string(strTodelete) is not matching to column7 and date that equal to currentnt date.
dt_Data_Delete=dtFormat.Select(“([Column7]<>'”+strToDelete+“’ and [Column0]=”+str_gnDateAllTab+“’ )”)

But is is showing error at <> saying invalid constant.
Can any one suggest a way to get string value that is not equal to the strings in column7.
Thanks and regards,

dt_Data_Delete=dtFormat.Select("[Column7]<>'"+strToDelete+"' and [Column0]='"+str_gnDateAllTab+"'")

Thanks a lot