how to read selection-screnn values into internaltable

Hi Experts,

how to read selection-screnn values into internaltable.that selection values are alphanumaric values.....

Example:selection low value is 100 and high value is 100b i want to read low value and between high values....there records are 100...100a...10b i want to read full reacords to internal table.......

thanks&regards

Rahul