Select a cell with what looks like number in your Excel spreadsheet and look
at the value in the Formula bar. If the value looks like:
123 then it is a numeric value.
If it looks like:
'123 then it is a Text value.
If you don't apply any alignment format in the cell, text value is aligned
left and numeric value is align right by default.
What I nornally do with a mixed Column in Excel, says, Column A, is to
create an extra Column next to it and use the Spreadsheet function Text(
{cell} , "General") to convert both Text and Numeric values to purely Text.
When I link or import the data from the spreadsheet, I ignore the original
column and use the (calculated) column whose values are all Text.