Search Document command (Edit menu)
Use this command to replace current word with an expanded word found in current document. This command searches current document for words which begin with the current word, inserts the found word into the active document, or presents Search Result dialog box if there are more than one matching words.

For example, type "str" and run this command, you can choose from "strcpy", "strcat", "strlen", etc.

Shortcuts
Keys:    Shift+F2